Needing only 775 more delegates to capture the Republican nomination, Trump has the chance to get almost half way home with the 367, mostly winner-take-all, delegates up for grabs on March 15.
A survey of the national polling data for these states has Trump leading with runaway margins in all states except Kasich's home state of Ohio, with Trump leading by the slimmest of margins, but Kasich picking up momentum.
If Trump runs the board on Tuesday, he will be unstoppable -- almost no realistic way to keep him from winning the magic number of delegates to clinch the nomination.
This is also a true test for Rubio and Kasich. A president is usually nonviable if they cannot be counted upon to win their own state, with only three presidents in history winning without their state of residency (James K. Polk, Woodrow Wilson, and Richard Nixon).If Rubio and Kasich lose, especially by overwhelming numbers, Trump's ability to call for their exit grows exponentially as they have lost significant political clout.
But there's also one other factor new to this race -- the pollsters just haven't been able to predict the races as closely as they have in the past.
Cruz, Rubio, and Kasich are all banking on this. But at some point after all the votes are counted Tuesday night, there has to be that moment of truth in all three of these campaigns.
An early finish to the Republican race may hurt Trump far worse than an embittered fight to the finish. He won't get as much press coverage, he'll have to rehone his message to the Democratic candidates, and he'll have to accomplish the traditional 'reconciliation' tactics done in all candidacies to secure both the party vote and invite the center.
This last point may be Trump's hardest task: how do you reconcile with those backing candidates that he's basically bullied for the past six months?
Even worse, what if the final three candidates refuse to endorse him in the end? Will their supporters naturally vote for him solely on party faithfulness?
So while the stop Trump movement may in fact be dead on Tuesday from the Republican perspective, from the Democrats' it's just beginning.
No longer will the strategy be about maps and numbers, but about one simple aspect: how do the Democrats get out the vote against a Republican candidate driving historically high turnout numbers?