OFF TO THE RACES: Trump, Clinton maintain their leads
Our latest NBC|SurveyMonkey poll shows Donald Trump and Hillary Clinton with big leads nationally heading into tonight's primaries.
You can follow developments throughout the day today on our liveblog.
The big picture today, from the New York Times: "If Mr. Trump loses Ohio (possible) or Florida (less likely) and wins less-than-commanding victories in Illinois, Missouri and North Carolina, he would face the strong possibility of falling short of a delegate majority and entering a contested Republican convention this summer. But with victories in the home states of two of his rivals, he could end the campaigns of Gov. John R. Kasich of Ohio and Senator Marco Rubio of Florida, leaving Senator Ted Cruz of Texas as the only candidate still standing in his way."
And from the Washington Post: "Presidential hopefuls in both parties made frenetic pitches across the Midwest and Southeast on Monday on the eve of presidential primaries in five states that could shore up the two front-runners — or breathe new life into the lagging campaigns of their challengers."
The Associated Press: "Republicans Marco Rubio and John Kasich are fighting for their political futures Tuesday, desperate for wins in their home states of Florida and Ohio to keep their White House hopes alive and complicate Donald Trump's path to the nomination. Democratic front-runner Hillary Clinton is hoping to keep rival Bernie Sanders from building new momentum in the Midwest."
And the Wall Street Journal: "In a whirlwind of events on the eve of Tuesday's primaries, Donald Trump aimed to sideline two Republican rivals on their home turf by adding a stop in Ohio to chase down Gov. John Kasich and scoring an endorsement from Florida's attorney general over home-state Sen. Marco Rubio."
CLINTON: She said at an MSNBC town hall last night that Trump is "inciting mob violence."
CRUZ: The Washington Post notes that he's finding some unlikely allies. "As Cruz hopes to land a knockout blow against Sen. Marco Rubio in Florida and narrow the primary contest to a two-man race between himself and Donald Trump, he is increasingly trying to appeal to two very different groups: working-class voters who may find themselves drawn to Trump, and voters from the traditional political establishment who want to stop him."
KASICH: In his home state paper: "In response to a question, Kasich said he has only now begun challenging Trump's tactics in campaign rallies that have sometimes turned violent because he wasn't fully aware of them before."
RUBIO: Benjy Sarlin writes that Rubio is using what appear to be the final days of his campaign to make a nuanced critique of Donald Trump and of the country.
Can he pull out a win in Florida? It would take "a miracle."
He reflected on his bid in an interview with the Miami Herald.
SANDERS: He said in last night's town hall that he ran as a Democrat for "media coverage." MORE: "In terms of media coverage, you have to run within the Democratic Party," he said, adding that MSNBC "would not have me on his program" if he ran as an independent."
His wife, Jane, toured Joe Arpaio's "tent city" jail.
TRUMP: POLITICO reports on concerns about Trump campaign manager Corey Lewandowski. "In interviews with more than 20 sources who have dealt with Lewandowski during his nearly year-long tenure with the Trump campaign and in his previous job with the Koch brothers-backed advocacy group Americans for Prosperity, complaints emerged about Lewandowski being rough with reporters and sexually suggestive with female journalists, while profanely berating conservative officials and co-workers he deemed to be challenging his authority."
The DSCC is working to paint GOP Senate candidates as part of "the party of Trump."
With surrogates like these... Ben Carson, on Trump: "The way I look at it, even if Donald Trump turns out not to be such a great president - which I don't think is the case, I think he's going to surround himself with really good people - but even if he didn't, we're only looking at four years."
*** Tuesday's "Andrea Mitchell Reports" line-up: NBC's Andrea Mitchell is live in Miami previewing tonight's big primary contests with Tad Devine - Senior Advisor Sanders for President; the New York Times' Ashley Parker covering the Trump campaign; the Washington Post's Ruth Marcus and Chris Cillizza; and our team of NBC reporters on the campaign trail in Ohio and Florida.