It all depends on Florida and Ohio, right? Actually, I think it’s more accurate at this point to say “it all depends on Ohio.” Florida is gone. Trump will win easily, which in one fell swoop will move him eight percent closer to the 1,237 delegates he needs to clinch the nomination. Even with Florida in his pocket, though, so many delegates have been spread across so many candidates at this point that he’ll still have work to do. Ohio is crucial twice over, first because it’s a big delegate windfall (with 66 at stake, it would move Trump another five percent closer to clinching) and second because it’s a bellwether of how he may perform in other northern and midwestern states to come. If he surprises Kasich tonight and takes Ohio, odds are he’s going to clean up in Illinois and Missouri too. If he doesn’t, and Cruz surprises him in the latter two states, we may be staring at a floor fight in July. Dave Wasserman, FiveThirtyEight’s elections guru, goes so far as to say that IL and MO are the ones to watch tonight, not FL and OH. If Cruz really is a serious threat to beat Trump head-to-head in a two-man race, we should see some evidence of it in those two states. If we don’t, get ready for a convention brought to you by Trump Inc.

If Trump sweeps Florida, Illinois, Missouri and Ohio, he will have at least 748 delegates and would need to win only 44 percent of all remaining delegates, a remarkably low bar, potentially ending the nomination fight.

If Trump loses Ohio but still wins Florida and sweeps Illinois and Missouri, he would need to win 50 percent of all other remaining delegates, a slightly higher bar but still very doable — and he would probably still be “on pace” for the nomination according to our delegate targets. But if Trump were to lose both Ohio and Florida, along with, let’s say, half of Illinois’s and Missouri’s districts, he could find himself needing to win 63 percent of remaining delegates to clinch the nomination, a much less plausible goal, considerably raising the odds of a contested convention in Cleveland.

As I say, he’ll win Florida so he won’t face Wasserman’s worst-case scenario. The question is whether Cruz overperforms in Illinois and Missouri, which would preclude the best-case scenario as well. The polls in those states show Trump leading him narrowly, by 6.5 percent in IL and by 7 in MO. That sounds like a recipe for a fairly even split of delegates, but appearances are deceiving in this case: Both states are “proportional” by congressional district, but each congressional district awards their delegates in a winner-take-all fashion. (The statewide winner gets some “bonus” delegates as well.) In other words, if Trump beats Cruz 35/34 in every one of Illinois’s and Missouri’s districts, he would win every delegate despite the razor-thin margin. He could pile up an enormous delegate lead tonight, requiring Cruz to dominate him in the primaries to come to prevent him from reaching 1,237. And there are structural factors working against Cruz. Missouri, for instance, is an open primary, so Democrats and indies can cross over for Trump. And in Illinois, the fact that Kasich and Rubio are still in the race will make it harder for Cruz to edge past Trump in more centrist urban districts, even if anti-Trump voters are out in force.

But wait, say Cruz fans. If Trump sweeps Florida, Illinois, Missouri, and Ohio, that’s actually a good thing since it’ll mean Kasich and Rubio are done. Finally we get our two-man race, with anti-Trumpers unifying behind Cruz. Cruz stomps him the rest of the way! No one’s more excited for that scenario, in fact, than Team Cruz itself, which laid out its plan to win a head-to-head race with Trump for Politico yesterday. Er, okay, but the math is what it is. And per Tim Alberta, the math ain’t good:

Trump victories in those two states would almost certainly eliminate both Kasich and Rubio while stretching his lead over Cruz to at least 300 delegates. At that point, the billionaire front-runner would be well more than halfway to the 1,237 delegates needed to clinch the GOP nomination, and Cruz would find it nearly impossible to prevent him from getting there, for two reasons: The race heads into Trump-friendly territory in April and beyond; and contrary to popular belief, many of the states voting after March 15 are not winner-take-all, meaning that Trump will continue to collect plenty of delegates even in contests where Cruz defeats him head to head…

The bottom line: If Trump carries both Florida and Ohio, and performs to expectations in the other three states, he’ll emerge from March 15 with at least 700 delegates and perhaps 750 or more. In a two-man race against Cruz, Trump would then need to win somewhere in the ballpark of 45 percent of all remaining delegates to reach 1,237, a highly attainable goal given the hospitable map and the number of proportional contests ahead.

All of which explains why Cruz, even if he won’t admit it publicly, needs either Kasich or Rubio to win their home state Tuesday — not just because it would deprive Trump of a large winner-take-all prize in the short term, but because it’s the only way that a second opponent can stay in the race and further divide the delegate pie, preventing Trump from reaching 1,237. Of course, a three-way race would eliminate whatever chance Cruz has of reaching 1,237 himself, but the schedule of states ahead makes that outcome virtually impossible anyway.

“All we have to do in a two-person is, we need to win 55-45,” said Cruz’s pollster to Politico. But they’d have to do that on less favorable electoral terrain, they’d have to do it consistently, and they’d have to do it knowing that Trump will continue to add delegates to his total in proportional states whether Cruz wins the state or not. Stuart Stevens, one of Romney’s top advisors four years ago, argued today that Trump could conceivably win enough delegates tonight that he may clinch the nomination late this spring even if he ends up on a losing streak against Cruz. As long as he’s losing narrowly in proportional states, piling up plenty of delegates in the process, he’s getting closer to 1,237. (For that reason, Stevens thinks a three-man race with Kasich hanging around and bleeding some centrist votes from Trump is more likely to stop him than a two-man race, since Kasich will be peeling off delegates in proportional states too.) Team Cruz’s strategy seems far-fetched in other ways too. Cruz’s strategists told Politico they need to win decisively in the two states voting next week, Arizona and Utah, but Arizona seems more likely to favor Trump. He’s the most vocal border hawk in the race; he has the endorsements of Jan Brewer and Joe Arpaio; and he’s ahead in the few polls taken there right now. A Trump sweep tonight would leave Cruz with no margin for error, yet there’s already an “error” looming in AZ. Team Cruz is also counting on rapid consolidation of the rest of the party behind him in late March and early April, ahead of the next big round of primaries, but they may be overestimating their support on that count. How many squishy establishment Republicans will throw in with a guy they dislike to begin with in a quixotic attempt to stop Trump if Trump sweeps tonight and the media moves into general-election mode between him and Hillary? There’ll be plenty of cries from the Beltway types whom Trump supposedly loathes to declare the race over and unify behind the winner.

The bottom line from Wasserman: Cruz needs to show some life tonight.

If Trump wins ALL 26 IL/MO CDs & 121 delegates, he's probably unstoppable even w/ OH loss. If Cruz wins at least a third, good sign for him.

— Dave Wasserman (@Redistrict) March 15, 2016

If Cruz pulls off an upset in MO & comes close in IL, odds of contested convention would rise dramatically. OH less of an indicator.

— Dave Wasserman (@Redistrict) March 15, 2016

I’ll leave you with a prediction: I think Trump will upset Kasich in Ohio and tomorrow everyone will be chattering about how the left’s moronic attempt to confront Trump at his rally in Chicago backfired spectacularly. We shall see.