Sen. Chris Murphy (D-Conn.), one of three negotiators in a pivotal immigration deal, spoke of some of the challenges facing Congress about the border.

Why it matters: The pivotal deal — which President Biden says would mark "the toughest and fairest set of reforms to secure the border we've ever had in our country" — has faced criticism and pushback from some Republican lawmakers, as well as former President Trump.

What they're saying: "The question is whether Republicans are gonna listen to Donald Trump who wants to preserve chaos at the border because he thinks that it's a winning political issue for him or whether we are gonna pass legislation," Murphy said on CNN's "State of the Union" Sunday.

• The bill could be ready to be on the Senate floor as early as next week, according to Murphy, though he said it would not arrive in that time frame "if Republicans decide that they want to keep this issue unsettled for political purposes."

The Connecticut Democrat said he thinks there are many Republicans in the Senate who are sincere about trying to come together and "do our job."

• "Let's also be cognizant of the fact that if we don't pass this bill, Ukraine won't get its military funding," Murphy added.
• "So, the consequence of failure here is not just that we keep immigration as an open issue available for Donald Trump to exploit in the next election. It is also that Ukraine loses this war, and that Russia marches its army to the edge of Europe," he said.
• "That would be catastrophic for the United States and for the whole world," he added.

Sen. James Lankford (R-Okla.) also expressed frustration with the GOP during an interview on "Fox News Sunday."

• "It is interesting, Republicans four months ago would not give funding for Ukraine, for Israel and for our southern border because we demanded changes in policy," Lankford said. "So we actually locked arms together and said, 'We're not going to give you money for this. We want a change in law.'"
• "Now it's interesting, a few months later, when we're finally going to the end, they're like, 'Oh, just kidding. I actually don't want a change in law because it's a presidential election year.'"
• "We all have an oath to the Constitution, and we have a commitment to say we're gonna do whatever we can to secure the border," he added.

Catch up quick: A bipartisan group of senators recently reached a deal that would force the federal government to shut down the border for migrants crossing illegally during surges and expedite the asylum process, Axios' Stef Kight reports.

• The agreement would automatically reject migrants and asylum seekers from crossing the border illegally once the daily average for border crossings surpasses 5,000 over a week or crossings surpass 8,500 on a single day, sources told Axios.

Biden said the law, if passed, would give him "a new emergency authority to shut down the border when it becomes overwhelmed," per a Friday statement.

• "And if given that authority, I would use it the day I sign the bill into law," he said.

Yes, but: Trump, who has based much of his 2024 presidential campaign on "Biden's border crisis," has been a fierce opponent of the bill.

• At a rally in Las Vegas over the weekend, Trump blasted the bill, saying "there is zero chance I will support this horrible open borders betrayal of America."
• "I'll tell you what ... I'd rather have no bill than a bad bill," he added.

Go deeper: Senators zero in on high stakes border deal