With the next round of primaries looming, Bernie Sanders appeared Monday at a rally in Youngstown, Ohio, to press the arguments about trade that worked so well for him in Michigan.

Another Tuesday in March; another crucial set of primaries. After the violent clashes in Chicago on Friday night, it’s back to the nitty-gritty of votes and delegate counts. By Tuesday night, Donald Trump could be well on his way to wrapping up the Republican nomination, or he could be facing the prospect of a fight all the way to the Convention. On the Democratic side, we will find out whether Bernie Sanders can build on his surprise victory in Michigan last week and deliver another blow to Hillary Clinton.

Five states will be holding primaries: Florida, Illinois, Missouri, North Carolina, and Ohio. In the G.O.P. contests, which also include a caucus in the Northern Mariana Islands, more than three hundred and sixty delegates will be up for grabs, which is about a seventh of the total required for the nomination. (That one-seventh figure doesn’t include superdelegates, who are fewer in number and less powerful in the Republican Party than in the Democratic.) Adding to the stakes for the Republicans, Florida and Ohio are winner-take-all votes, while Illinois will award the great majority of its delegates to the candidate who finishes in first place.

If Trump wins these three states—and the latest opinion polls suggest that this is a real possibility—he will pick up more than two hundred delegates, to add to his current total of four hundred and sixty. Because Trump is also leading the polls in Missouri and North Carolina, it is conceivable that he could end the night with more than seven hundred delegates, and with a lead over the second-place candidate, Ted Cruz, of about three hundred delegates.

Such an outcome would leave Trump well short of the twelve hundred and thirty-seven delegates he needs to have a majority of the elected delegates. But the dynamics of the race would be overwhelmingly in his favor. If Trump wins Florida, Marco Rubio will almost certainly drop out of the race. If Trump wins Ohio, John Kasich is also likely to exit. That would leave Trump in a two-man race against Cruz.

With nineteen primaries and caucuses remaining, Trump would need to pick up roughly half of the remaining delegates to achieve a majority, and the geography of the race would strongly favor him. Cruz, with his following of dedicated conservatives, does best in caucuses and in the South. But the only remaining Republican caucus is in Utah, which votes on March 22nd, and the only Southern state yet to vote is West Virginia, which arguably isn’t part of the South at all. For Trump, by contrast, the primary map looks very favorable. In big states like New York, New Jersey, and Pennsylvania, he is running well ahead in the polls.

Of course, as we rediscovered in Michigan, the polls aren’t always reliable. For what they are worth, however, they suggest that Trump has a big lead in Florida, while the contest in Ohio is very close. A Quinnipiac University poll that was carried out over the weekend and published on Monday showed Trump leading Rubio by twenty-four percentage points in Florida. Another new survey, from Monmouth University, showed Trump in front of Rubio by seventeen percentage points. (In both polls, Cruz was in third place.) “At least when it comes to this presidential primary, Florida might change its nickname from Sunshine State to Landslide State,” Quinnipiac’s Peter A. Brown said in a statement. “Sen. Marco Rubio, who has staked his future on [winning] his home state, looks like he’ll soon be toast.”

On Monday, Trump cancelled an event in Florida, an indication that he is confident of winning there, and added one in Youngstown, Ohio. According to the Quinnipiac pollsters, who also surveyed Ohioans over the weekend, Trump and Kasich are now running even in the Buckeye State, with each getting thirty-eight per cent of the vote. (Cruz is in third place, at sixteen per cent.) An NBC News/Wall Street Journal poll, which was carried out from Wednesday to Friday of last week and published on Sunday, showed Kasich with a six-point lead over Trump: thirty-nine per cent to thirty-three per cent.

As the sitting governor of the state, Kasich has a big advantage in organization and endorsements, including that of Mitt Romney, which may yet see him home. But Trump is making a fight of it. On Monday, he claimed to have received the endorsement of a local icon, Pete Rose, the disgraced Cincinnati Reds great. On his Twitter feed, Trump showed a photograph of a baseball signed by Rose, with the inscription “MR. TRUMP PLEASE MAKE AMERICA GREAT AGAIN.”

If Kasich does manage to hold off Trump, he will still be far, far behind in the delegate count. But, assuming Rubio drops out, the Ohio governor will be the sole remaining moderate conservative alternative to Trump. (Please note: I use the term “moderate conservative” only in the context of this national contest. The last time I applied it to Kasich, a number of Ohioans contacted me and pointed out that his record there is very conservative.)

If Kasich were to win Ohio, he would go into some big primaries in the Northeast and on the West Coast with the hope of picking up Republican voters and big-money donors who previously had been planning to back Rubio. He still wouldn’t have much hope of overtaking Trump, but his strategy would be to make it to the Convention, where he could take his chances in a floor battle or an attempted establishment maneuver. Clearly, things will be easier for Trump if he can knock Kasich out of the race on Tuesday.

On the Democratic side, if you don’t count Party-appointed superdelegates, who are overwhelmingly in Clinton’s camp, the contest is now pretty competitive. Clinton has an estimated seven hundred and seventy-two delegates; Sanders has an estimated five hundred and fifty-one. On Tuesday, Clinton looks set to further extend her lead by winning in Florida and North Carolina, where the Democratic electorate includes a lot of minority voters. Between them, these two states have three hundred and sixty-seven delegates, and recent polls in both places show Sanders trailing by twenty points or more.

But that doesn’t mean the Vermont senator is destined for a bad night. Coming off his victory in Michigan, he has concentrated his efforts on Illinois, Missouri, and Ohio, which between them have four hundred and twenty-five delegates—more than Florida and North Carolina. Appearing in Youngstown on Monday, Sanders pressed the arguments about trade that worked so well for him in Michigan. Invoking the North American Free Trade Agreement, he said, “I proudly stood with the workers. Secretary Clinton stood with the big-money interests.”

If Sanders can somehow sweep these three Midwestern states, it will be something of an earthquake for the Democratic Party. Even if he won two of Illinois, Missouri, and Ohio, it would be another setback for Clinton. But, if she pulls out victories in the Midwest, it will help to steady her campaign. The latest polls suggest that the contests in Illinois and Missouri are very close, while Clinton retains a double-digit lead in Ohio. To repeat, these surveys should be treated with caution. In Michigan, the pollsters gravely underestimated turnout among young Sanders supporters. They might have done so again.

Given Sanders’s strength among white voters, demographics may again play a big role. Missouri and Ohio look pretty similar to Michigan: in each state, less than fifteen per cent of the population is black, and less than five per cent is Hispanic. Illinois is more diverse: close to thirty per cent of the electorate is black or Hispanic. Interestingly, though, it is in Illinois where Sanders appears to be making up ground, and he is doing it partly by criticizing Rahm Emanuel, the embattled mayor of Chicago. (During the nineteen-nineties, Emanuel worked for the Clinton Administration, and he now supports Hillary.) On Monday, speaking in Summit, Illinois, Sanders thanked Emanuel for not endorsing him and said that he sympathized with the Chicago residents who were seeking the mayor’s resignation. Sanders was planning to end his day at a big rally in Chicago.

We will find out tomorrow night whether this push in Illinois pays off. And we will find out much else besides.