Former President Trump and President Biden vaulted toward their parties' respective nominations on Super Tuesday, snatching the overwhelming majority of delegates up for grabs across more than a dozen states.

Why it matters: On the biggest voting day before November, the frontrunners won the two states with the most delegates: Texas and California.

• Former UN Ambassador Nikki Haley won only one state: Vermont.
• In California, Rep. Adam Schiff (D-Ca.) placed first in the state's open primary for the seat held for decades by the late Democratic Sen. Dianne Feinstein, per AP. Schiff will likely face Republican Steve Garvey, a former MLB star, setting up an easier path to take the solidly Democratic seat.
• In Texas, Rep. Colin Allred was projected to win the Democratic Senate primary and will face Republican Sen. Ted Cruz in November.

Go deeper: See the state-by-state Super Tuesday primary results

Editor's note: This story was updated with new details and developments.

Nikki Haley's unwanted fan

The Biden campaign has moved from focusing on attacking Nikki Haley to using the GOP primary candidate's words against Trump, Axios' Sophia Cai and Justin Green report.

• Whether it's on X or Truth Social, the campaign repeatedly clips and promotes every attack she has made against Trump.

The bottom line: "Democrats want nothing more than for Donald Trump to be the nominee because they know they will beat him in November," Haley campaign spokesperson Olivia Perez-Cubas told Axios.

• "It's not a coincidence that she's their best surrogate," Trump campaign spokesperson Steven Cheung told Axios in a statement.

Super Tuesday's most compelling race is for California Senate

In California's open Senate race an open primary will send the top two vote getters to a second round in November — regardless of party.

State of play: Two prominent House Democrats, Rep. Adam Schiff and Rep. Katie Porter, are scrambling after a late surge by a Republican former Dodgers star, Axios' Andrew Solender and Stephen Neukam report.

• Schiff leads the RealClearPolitics average of polls in the race, followed by Republican Steve Garvey, who played first base for the San Diego Padres and Los Angeles Dodgers in the 1970s and 80s.
• Porter is running a close third, and Rep. Barbara Lee is a distant fourth.

Between the lines: The state's election rules mean a long and ugly fight if two Democrats qualify for the solidly Democratic seat — and a relatively easy win for a Democrat if a Republican makes the cut.

• Schiff and a super PAC that backs him have spent millions attacking Garvey in an end-around way to push him into the top two, CNN reports.

Go deeper.

🎤 Swiftie alert! Taylor Swift looks to get out the vote

Taylor Swift encouraged her more than 280 million Instagram followers to make a plan to vote on Super Tuesday, Axios' Erin Doherty writes.

• The pop superstar did not support any candidate.

Why it matters: Swift has not endorsed a candidate for president in 2024, but MAGA acolytes have publicly fumed for her to "stay out of politics" after the New York Times reported that Biden's campaign is vying for her endorsement, Axios' Natalie Daher previously reported.

• "I wanted to remind you guys to vote the people who most represent YOU into power," Swift wrote on her Instagram Story. "If you haven't already, make a plan to vote today."

Flashback: Swift endorsed Biden during the 2020 presidential election. His re-elect campaign is hoping for a repeat in 2024 to help him appeal to the crucial youth voter base.

View Swift's IG... Go deeper: It's Taylor Swift's world and we're just living in it

🧮 Super Tuesday states: When results are expected

The soonest Donald Trump could amass enough delegates to clinch the GOP nomination is March 12 — a week from Tuesday, when Georgia is among the states voting. Trump's campaign expects he'll clinch that day.

• Get wonky: Today's delegate math.

Here's tonight's timeline, via AP:

• 6 p.m. ET: Results expected in Iowa.
• 7 p.m. ET: Polls close in Vermont, Virginia. Caucuses convene in Alaska (Republicans only).
• 7:30 p.m. ET: Polls close in North Carolina.
• 8 p.m. ET: Polls close in Alabama, Maine, Massachusetts, Oklahoma and Tennessee. Most polls close in Texas.
• 8:30 p.m. ET: Polls close in Arkansas.
• 9 p.m. ET: Polls close in Colorado, Minnesota. Last polls close in Texas. Caucuses convene in Utah (Republicans only).
• 10 p.m. ET: Polls close in Utah (Democrats only).
• 11 p.m. ET: Polls close in California. Voting expected to end in Utah (Republicans only).
• Midnight ET: Voting ends in Alaska (Republicans only).

📺 At 10 p.m. ET, ABC, CBS and NBC will carry hour-long Super Tuesday special reports.

🗳️ Sinema heads for exit

Arizona Sen. Kyrsten Sinema made her own headline Tuesday by announcing she won't seek a second term, putting to rest months of speculation about her political future.

• Why it matters: Her announcement opens the door for a likely bitter match-up between Republican Kari Lake and Democratic Rep. Ruben Gallego in a contest that could determine control of the Senate, Axios Phoenix's Jessica Boehm and Erin Doherty write.

Between the lines: Lake in a statement Tuesday took the opportunity to knock Gallego: "Senator Sinema had the courage to stand tall against the far left in defense of the filibuster — despite the overwhelming pressure from the radicals in her party like Ruben Gallego who called on her to burn it all down."

• Get Axios Phoenix ... Read more on Sinema's mutually assured destruction.

🕰️ Flashback: The ex-president who ran again and won

Donald Trump is looking to do something only Grover Cleveland has done before in U.S. history: defeat the opponent who booted him from office, Axios' Emma Hurt reports.

• In 1892, Democrat Cleveland came back to defeat Republican Benjamin Harrison, who had beat him in 1888.

Zoom out: Other ex-presidents have unsuccessfully sought non-consecutive second terms, including Martin Van Buren and Theodore Roosevelt, Politico Magazine reported.

The big picture: Republican voters today see Trump as an incumbent, veteran GOP pollster Whit Ayres told CNN.

• To understand his dominance, Ayres said, "What we really need are entrance polls and exit polls from the 1892 Democratic coalition for Grover Cleveland. That's the analogy: a former president running again to defeat the guy who beat him."

Biden wins Iowa Democratic caucuses: AP

It was the first of many expect victories Biden is expected to notch on Super Tuesday.

The big picture: Iowa Democrats delayed releasing their results to adhere to a Democratic National Committee rule change.

• Democrats in the state have been returning presidential preference cards since January, but the results have been held until Tuesday.

Flashback: Trump dominated the GOP Iowa caucuses, winning 98 out of 99 counties across the state.

• 📧 Get Axios Des Moines.

Trump trials timeline: 3 big cases in limbo

Trump isn't just winning primaries, his legal team's delay tactics are showing success in the courtroom too, Axios' Dave Lawler writes.

Why it matters: The timelines of three of his four criminal cases are now in limbo, and the trials may not even begin before November. If he wins the presidency before standing trial, he could escape prosecution altogether.

• "If you were a betting man, the hush money [case] is the only one I would bet on" happening before the election, Joshua Naftalis, a former federal prosecutor in New York and now a partner at Pallas, previously told Axios.

What's next: Trump's New York hush money trial is still on track to begin March 25. It is widely seen as the weakest case.

• Go deeper.

Biden's "uncommitted" voter problem

President Biden is facing an unexpected contender on Super Tuesday — the "uncommitted" vote, Axios' Sareen Habeshian writes.

Why it matters: The movement is building momentum after over 100,000 Michigan Democratic primary voters cast ballots for "uncommitted" in protest of the Biden administration's support for Israel's government in its war with Hamas.

• Arab American and Muslim voters upset with Biden's handling of the war are hoping to send him a message at the polls, as they did in Michigan where the same voters were key to his 2020 win in the swing state.

Colorado's Trump votes will count after all

Colorado voters are going to the polls a day after the Supreme Court unanimously ruled that Trump can't be barred from its primary ballot under the 14th Amendment.

Why it matters: It was a major win for the GOP presidential frontrunner and forces Democrats to come to grips with a clear reality — they're going to have to defeat him without much help from the courts, Axios' Zachary Basu writes.

Flashback: The state's Secretary of State Jena Griswold, who supported Trump's removal, said yesterday she was "disappointed" in the court's decision, Axios Denver's Alayna Alvarez reported.

• "Colorado should be able to bar oath-breaking insurrections from our ballot," she said.

Reality check: Trump's name has been on Colorado's ballot the whole time.

Go deeper: Reality bites Democrats: Courts won't save them from Trump ... Get Axios Denver

📺 What we're watching: 3 time slots

Check in three times on Super Tuesday results, and you'll get much of it.

• 7:30pm ET: Polls close in North Carolina, where the exit polls will have hints on November.
• 8pm ET: Most polls close in Texas, where Democrats Rep. Colin Allred and state Sen. Roland Gutierrez are facing off to challenge Republican Sen. Ted Cruz.
• 11pm ET: Polls close in California, with a four-way Senate race and tight House Democratic primaries in GOP-held Biden districts.

Get Axios Sneak Peek.

Texas holds second-biggest Super Tuesday prize

Democratic voters in Texas are choosing a nominee to face U.S. Sen. Ted Cruz.

• Why it matters: Cruz is seen as one of a few vulnerable Senate Republicans in this year's elections — even though Texas hasn't sent a Democrat to the U.S. Senate since 1988, Axios Dallas' Michael Mooney reports.

State of play: Dallas Rep. Colin Allred is running against San Antonio-area state Sen. Roland Gutierrez in the primary.

The big picture: Presidential candidates are competing in Texas for the second biggest Super Tuesday prize for each party, behind California.

• 161 delegates are at stake for the GOP and 244 for Democrats.

What we saw: Axios Austin' Nicole Cobler observed that when she voted at noon at her local public library it was busier than she expected — but still no wait to speak of.

💥 Spoiler candidates hang in race

Other candidates not named Trump or Biden have mounted long-shot independent or third-party bids, including Robert F. Kennedy Jr. and Rep. Dean Phillips.

Why it matters: Independent or third-party bids, considered "spoilers" could tip the election in favor of Biden or Trump in a razor-thin rematch, Axios' April Rubin and Erin Doherty write.

• Third-party candidates could capture the large percentage of voters uninspired by the two historically unpopular frontrunners' candidacies.

Phillips, a three-term congressman, is the most notable Democratic candidate challenging Biden's re-election campaign, although he hasn't yet won any delegates.

• Self-help author Marianne Williamson announced last week that she was re-entering the race. She also has not won any delegates in the Democratic primary.

Zoom in: Kennedy, running as an independent, could pose the biggest threat to the two likely nominees, as he boasts strong national name recognition.

• Meet the spoilers.

🎈 Dispatch: Trump party at Mar-a-Lago

Trump's celebration was in a ballroom at Mar-a-Lago in Palm Beach, Florida, where supporters crowded in to watch primary returns and cheered as states were called for the former president, Axios' Sophia Cai reports.

• The crowd included several members of Congress, including Reps. Byron Donalds (R-Fla.) and Marjorie Taylor Greene (R-Ga.).

The big picture: Trump's team has signaled that after a big haul of delegates Tuesday, it expects him to clinch the GOP nomination in the next several days.

• Trump senior adviser Chris LaCivita was asked whether he thought Nikki Haley had a chance to win a state tonight.  "Who?" he said.

Axios Local postcard: MAGA reigns

In an expected win, Lt. Gov. Mark Robinson clinched the GOP nomination for N.C. governor Tuesday, Axios Charlotte's Katie Peralta Soloff reports.

• Donald Trump recently endorsed Robinson, calling him "Martin Luther King on steroids."

Why it matters: Robinson will face Democratic N.C. Attorney General Josh Stein in one of the most closely-watched governor's races in the country.

• After an improbable and controversial political ascent, Robinson, a pastor from Greensboro, is one step away from becoming the first Black governor of North Carolina.

He rose to fame after a 2018 viral video from a Greensboro city council meeting in which he advocated for gun rights, Axios Raleigh's Lucille Sherman reported.

In Tennessee politics, Trump also remains a dominant force, Axios Nashville's Adam Tamburin reports.

• Democratic primary voters overwhelmingly backed Biden, who ran unopposed in Tennessee.
• A small portion of Democratic voters in Tennessee selected "uncommitted" on their ballots.

California's plan to transform its mental health system is on the ballot

California voters Tuesday will decide the fate of Gov. Gavin Newsom's sweeping plan to overhaul the state's approach to mental health treatment and homelessness, Axios San Diego's Andrew Keatts writes.

Why it matters: The state spent $17.5 billion on homelessness-related programs from 2018-2022, only to watch its homeless population jump by 40% over about the same time frame.

State of play: Proposition 1 would let the state borrow $6.4 billion to build mental health treatment beds and supportive housing for homeless residents.

• It also would require counties to redistribute state dollars toward the most severe behavioral health needs and away from prevention.

Reality check: Prop 1's estimated 6,800 new treatment beds would not even meet the state's estimated 8,000-bed shortage.

• It also would allow funding for facilities that involuntarily hold patients — a position that outraged some mental health advocates.

Go deeper: California's plan to transform its mental health system

Allred takes lead in Texas Democratic Senate primary: AP

Rep. Colin Allred took a massive lead over Texas state Sen. Roland Gutierrez in the Texas Democratic Senate primary.

• Allred, a Dallas civil rights lawyer and former NFL player, has been a fundraising juggernaut. As of Feb. 14, he had raised more than $21 million for the campaign, per FEC data.

Trump will speak at Mar-a-Lago

The former president will give remarks from his Palm Beach, Florida club at 10:15pm ET, Axios' Sophia Cai reports.

• Haley doesn't have a scheduled event.

📈 Trump senior adviser says VP list "growing"

Trump adviser Jason Miller told NBC News on Tuesday that his boss' already long list of potential veeps is growing, Axios' Natalie Daher writes.

• Miller, a key architect of the first Trump administration's policy, said: "There are so many prospects that are out there," adding that the team is "quite a ways away" from selecting someone.

Among the possible picks: South Carolina Sen. Tim Scott, Rep. Elise Stefanik, Gov. Kristi Noem and businessman Vivek Ramaswamy.

Trump pivots to general election in Super Tuesday speech

During remarks at his Super Tuesday watch party, former President Trump avoided mentioning Haley, but he chided President Biden in an apparent pivot to the general election.

Why it matters: "We want to have unity and we are going to have unity," Trump said from Mar-a-Lago, as he bashed his likely Democratic challenger in the November general election.

• "We're going to win this election because we have no choice," Trump said.
• The former president spoke after he was projected to win 11 states on Super Tuesday.
• "There's never been anything so conclusive," he said.

Haley dodges total Trump sweep

Haley's win in the Vermont GOP primary helps her avoid the embarrassing loss of all 15 Republican primary contests Tuesday.

• The contest was widely seen as her best shot at victory given the state's moderate voter base.
• It's her second win of the GOP primary following a victory in Washington, D.C.

Biden says Trump is "driven by grievance and drift"

Biden in a statement Tuesday warned that a second Trump term would "drag us backwards into the chaos, division, and darkness that defined his term in office," Axios' Erin Doherty writes.

Why it matters: As the Biden campaign pivots to the general election, the president is increasingly presenting former President Trump as a treat to the nation

• "[Trump] is driven by grievance and grift, focused on his own revenge and retribution, not the American people," Biden said in a statement that also touted his accomplishments in office.
• "Today, millions of voters across the country made their voices heard — showing that they are ready to fight back against Donald Trump's extreme plan to take us backwards," Biden said.

Haley campaign honored by "millions" who voted against Trump

While Haley didn't deliver a speech Tuesday, her campaign issued a statement that it was "honored" to have received millions of votes, across 15 GOP contests.

The big picture: The campaign noted Haley became the first Republican woman to win two presidential primary contests by taking Vermont — after D.C. last week.

• "Today, in state after state, there remains a large block of Republican primary voters who are expressing deep concerns about Donald Trump," Haley national spokesperson Olivia Perez-Cubas said in a statement.

Phillips considering next steps

Longshot Democratic presidential candidate Rep. Dean Phillips (D-Minn.) said he's assessing results after losing to Biden in his home state and all other primaries on Tuesday, Axios' Bec Falconer writes.

• Phillips said in a statement that while Democrat loyalists were "clearly, consistently, and overwhelmingly registering their preference" for President Biden, he believes former President Trump is "increasingly likely to defeat him in November."

Once he's reviewed all available data over the coming days, he said he'll "make a decision about how I can best help prevent that tragedy."

• He earlier jokingly congratulated his opponents, including the "uncommitted" option, in a post on X.

Don't forget: Phillips did win at least one county on Super Tuesday: Cimarron in the Oklahoma panhandle, which has a population of just over 2,000.

Trump foe Schiff locks down easier path to U.S. Senate

Democratic Rep. Adam Schiff and Republican Steve Garvey topped the primary field in California's U.S. Senate race Tuesday, advancing to a November general election, Axios' Stephen Neukam reports.

The big picture: For the first time in decades, Californians will not be represented by a woman in the Senate.

• Sen. Laphonza Butler (D-Calif.) was appointed to fill the seat of longtime Sen. Dianne Feinstein (D-Calif.), who died in September. But Butler decided not to run for a full term.

Utah GOP primary plagued by tech issues

President Biden won Utah's Democratic presidential primary on Tuesday, but the state's GOP results were delayed thanks to myriad issues with its new caucus system, Axios Salt Lake City's Kim Bojórquez reports.

Context: The Utah GOP opted to hold a presidential preference poll at caucus meetings this year, but many locations encountered long lines and technical difficulties, frustrating GOP voters and delaying results.

• Go deeper.