Former President Trump arrived Monday at the Lower Manhattan courthouse for the start of jury selection in his criminal trial.

Why it matters: The first-ever criminal trial of a former U.S. president — who happens to be a presumptive nominee — will put the long-expected collision between Trump's legal jeopardy and his presidential ambitions into sharp, stunning focus.

• Trump, who has denied wrongdoing and repeatedly called the trial a political witch hunt, said during brief remarks to reporters as he entered the courtroom that the trial "is an assault on America."
• Justice Juan Merchan declined a request from the defense to recuse himself from the case, per a pool report. He said he would not address the matter further.
• Merchan's interviews with news outlets and a podcast were one of the reasons he was asked to recuse.

State of play: Trump moved part of his campaign operation to New York over the weekend, and a massive security operation has descended around the courthouse for what could be two months or so.

Will Trump be in court and when?

• The trial isn't expected to be televised, per New York law. But it will reshape the presidential campaign in unprecedented ways.
• For at least four days a week, Trump likely will have to be in court, facing allegations that he falsified business records to cover up a hush-money payment to a porn star just before the 2016 election.
• He won't have to be in court on Wednesdays, so he'll likely use those days and weekends for campaign events.

Trump's team also will continue to treat every moment he's at a microphone outside the courtroom as a campaign event.

• His campaign has been in touch with surrogates about doing media hits about the election while he's in court, a person involved with the conversations told Axios.
• During his press conference with House Speaker Mike Johnson (R-La.) on Friday, Trump suggested he'll testify at the trial.
• That would be another unprecedented moment in a trial full of them — but many legal experts doubt he'll actually take the stand and risk having to answer a range of questions under oath.

How will jury selection go down?

Hundreds of prospective jurors were expected to show up at the Manhattan courthouse on Monday, when prosecutors and Trump's attorneys will begin a jury-selection process that could last up to two weeks.

• Jurors won't be asked about their political affiliations, but they will be asked questions about their news sources, whether they've worked for Trump or attended one of his rallies, and whether they've ever been members of the Proud Boys or the QAnon movement.
• Around the Manhattan Criminal Courthouse and Trump Tower — where Trump will stay during the trial — New York police will create no-go zones, increase security cameras and monitor social media to try to detect any threats, CNN has reported.

What is Trump on trial over, and who else might appear?

Prosecutors allege that the former president intentionally obscured business records to cover up a $130,000 payment that Michael Cohen, Trump's lawyer and fixer, made to Stormy Daniels in the months before Trump was elected president.

• Cohen, who's expected to be a key witness for the prosecution, has said he made the payment at Trump's instruction.
• Hope Hicks, a former Trump White House aide, also is expected to testify and provide key details on what was happening in the former president's inner circle in the days before the 2016 election.

The former president faces 34 felony counts in the case brought by Manhattan District Attorney Alvin Bragg.

• It's widely viewed as the weakest of Trump's four criminal indictments, but it's looking like the only one likely to wrap up before the Nov. 5 election.
• And a conviction in New York still could put Trump behind bars — theoretically, anyway.
• Bragg's prosecutors will argue that a felony conviction is in order because Trump committed a crime (falsifying business records) while trying to cover up another crime — breaking election law by scheming to cover up the payments to Daniels.

What do voters think of Trump's indictments?

Most voters think the charges in the hush-money case are serious, according to a Reuters/Ipsos poll released Wednesday, a sign that of the trial's stakes for Trump less than seven months before the election.

• Several polls have indicated that if Trump is convicted, he'll lose support among some voters in what's expected to be a tight race for the White House. Privately, his advisers are bracing for the possibility that he'll be a convicted felon before the election.
• "You only need one" conviction, "if you're sort of keeping score," Joshua Naftalis, a former federal prosecutor in New York, told Axios.
• "Trump doesn't need to be convicted four times. The point is, getting convicted once is devastating."

Go deeper: Trump hush money case: Meet the key players involved

Editor's note: This story has been updated with details on former President Trump's arrival at the Manhattan courthouse.