The Hill asked a number of commentators to predict what happens in today's Republican and Democratic primaries. Here's what they had to say.
Bradley A. Blakeman
Winners: Donald TrumpDonald TrumpTrump: 'I never did business with Cuba' USA Today in scathing editorial: Trump is 'unfit for the presidency' Obama administration officials ramp up push for Pacific pact MORE and Ohio Gov. John Kasich
Blakeman is a professor of public policy, politics and international affairs at Georgetown University and was a senior adviser to former President George W. Bush.
Former Rep. John LeBoutillier (R-N.Y.)
Winners: Trump, Kasich and Cruz
Trump and Cruz are going to emerge as the big winners today.
Rubio is going to get shellacked in Florida and drop out on Wednesday. He will NOT endorse The Donald – ever.
Kasich will win Ohio by 1 or 2 percentage points and will stay in the race.
Trump will win Florida big, and will average his usual 35 percent in Illinois, Missouri and North Carolina.
Cruz will place second in almost every state, and accumulate enough delegates to make the argument that only he can take on Trump and deny him the nomination. Cruz has flown under the radar lately — and that actually has calmed down his image a bit — thus making it more palatable for establishment GOP figures to hold their tongues and actually endorse Cruz in an effort to stop Trump.
The Stop Trump Movement — which will have spent over $10 million — will be deemed a complete flop.
LeBoutillier is a former Republican congressman from New York and is the co-host of "Political Insiders" on Fox News Channel.
Winners: Trump, Kasich and Cruz
Today has a chance to be the most consequential day of the entire Republican nomination contest.
Major battleground states Ohio and Florida are winner-take-all, and they can end the campaigns of their home-state candidates.
Rubio's campaign is running on fumes. He has no path to 1,237 delegates and he will likely be the first major party presidential candidate to lose his home state primary since 1992 (while a sitting state official).
I do not think Rubio can win Florida. He had a strong early voter turnout initially, but several factors have worked against him and his mediocre approval ratings in the state and break with the Tea Party over immigration have really hurt him. He needs huge South Florida turnout because that's his base, while Trump will run up the score in north Florida. The I-4 corridor from Tampa to Orlando will decide who wins. Florida is a closed primary — which benefits Rubio and Cruz and hurts Trump — but I expect a 6 to 8 percentage point win in Florida for Trump due to his momentum.
Ohio is a closer call, but I think Kasich has very real momentum there (as evidenced by 2012 GOP nominee Mitt Romney campaigning with him Monday at two stops). Kasich also has a real organization, and he has broad support, with an approval rating around 80 percent. I expect a comfortable Kasich win in Ohio of 3 to 5 points.
Most people don't realize Illinois, North Carolina and Missouri combine to have more delegates than Ohio and Florida.
I expect Cruz to win Missouri, Trump to narrowly win Illinois, and North Carolina could go either way.
Trump splitting Florida and Ohio means the race continues, likely with only three active candidates. Only six winner-take-all states remain (Arizona, Delaware, Nebraska, Montana, New Jersey and South Dakota). Cruz will need to rapidly unify the party behind him to overtake Trump as overall delegate leader.
I do expect an open convention that goes past the first ballot.
Mackowiak is a syndicated columnist; an Austin, Texas-based Republican consultant; and a former Capitol Hill and George W. Bush administration aide.
Winners: Trump and Kasich
Super Tuesday 2.0 is likely to be a very good day for Trump, and it could be a defining moment in the race. Trump will win Florida, North Carolina, Illinois and Missouri, netting his campaign in the neighborhood of 200 delegates out of a possible 367. That said, the main event is Ohio. Fortunately for the anti-Trump forces, Kasich will eke out a win in this winner-take-all state.
That leaves Trump as still the best-positioned candidate to secure the 1,237 delegates needed for the nomination, but to accomplish that he will have to win roughly 60 percent of the remaining delegates — a high bar, but certainly not impossible. Taking a step back and looking at the delegate math, a contested convention remains a 50/50 proposition.
O'Connell is the chairman of CivicForumPAC, worked on John McCainJohn McCainKerry: US 'on the verge' of suspending talks with Russia on Syria Trump, Clinton to headline Al Smith dinner Overnight Defense: Congress overrides Obama 9/11 veto | Pentagon breathes easy after funding deal | More troops heading to Iraq MORE's 2008 presidential campaign and is author of the book "Hail Mary: The 10-Step Playbook for Republican Recovery."
Former Rep. Bill Owens (D-N.Y.)
Winner: Hillary ClintonHillary Rodham ClintonTrump: 'I never did business with Cuba' Clinton’s sixth nerve palsy: What difference does it make? USA Today in scathing editorial: Trump is 'unfit for the presidency' MORE
The chaos in this year's presidential campaign continues to gather steam after Sen. Bernie SandersBernie SandersAnti-trade senators say chamber would be crazy to pass TPP Vulnerable NH Republican ties reelection bid to Trump Overnight Finance: Congress poised to avoid shutdown | Yellen defends Fed from Trump | Why Obama needs PhRMA on trade MORE's (Vt.) win in Michigan and with the polls confirming that the back-and-forth will likely continue between Clinton and Sanders — but with a significantly more civil tenor than the GOP. Close races in Illinois (Clinton's birthplace and a Democratic stronghold), Ohio and Missouri might not bode well for Clinton, as we've seen that Sanders has the ability to swing the close races into his column. My crystal ball shows Clinton securing 527 delegates with blowout wins in Florida and North Carolina and a single-digit win in Ohio.
Owens represented New York's North Country from 2009 until retiring from the House in 2015. He is a partner in the Plattsburgh, N.Y., firm of Stafford, Owens, Piller, Murnane, Kelleher & Trombley, PLLC.
Winners: Trump and Clinton
Expect Clinton and Trump to hold serve in the all-important Super Tuesday II states. Missouri, Ohio and Florida are integral to victory in November, cementing their status as the front-runners. However, a Fox News poll shows Trump and Kasich locked in a heated battle for Ohio, but given Trump's lead in Florida, Illinois and Missouri, a Kasich win in Ohio will be an afterthought. Rubio is poised for a shutout once again, thus ending his presidential ambitions.
Sanders is trailing in all Super Tuesday II states, yet do not expect Sanders to go quietly as he could replicate another surprise showing in Ohio, a la Michigan. Still, Trump and Clinton will only expand their leads in the delegate count, suggesting the end is near on both sides of the aisle.
Ham is author of the national bestseller, "The GOP Civil War: Inside the Battle for the Soul of the Republican Party." He is a contributor to the P.O.T.U.S. Channel on SiriusXM Radio and provides political analysis for the BBC. Follow him on Twitter @EKH2016.