Well, here it is: the decision day for two of the candidates in this race who have staked everything on winning their own home states. By doing so, they have likely mathematically eliminated themselves from getting the nomination by reaching 1,237 delegates, as we discussed yesterday for both Kasich and Rubio.

But by winning their home states, they can at least deny the delegates to Trump, which will exponentially increases the chances of a contested convention, and might justify (to their fundraisers) a pitch to stay in the race. But nothing less than an outright win will do in either case.

For both candidates, the outlook is frankly grim even if they win their home states. Rubio, at least, is smart enough to know it. He's cancelled all ad buys after Florida and seems to know that he is in this for one and only one purpose, which is to keep 99 delegates out of the hands of Trump. Even if he succeeds, it would not surprise me in the least to see him drop out shortly after Florida. Rubio knows that a four-man field is a gift to Trump and unlike Kasich, he loves America more than he loves himself.

Kasich, meanwhile, is in even more dire straits than Rubio, even though he stands a pretty good chance of winning his home state (better than Rubio does, for sure). Bu Kasich has been such a failure so far in this election season that even if he does win Ohio (and Rubio does not win Florida, he will still be behind Rubio in the delegate count. He's also finished behind Ted Cruz in states that ought to be in his wheelhouse (like Michigan) and who knows if he will be even on the ballot in Pennsylvania, which is another absolute must win state for him.

Nonetheless, if Kasich wins Ohio, there is absolutely no chance he will get out before the convention, even if he keeps on getting dead last in every state between now and then. Which is why, even though it would be great to keep Trump from getting these delegates, you can bet that Team Cruz is really hoping that Kasich does not win Ohio, even if that means Trump wins it.

Speaking of, it's kind of important for Ted Cruz to win a state today, as well. Not as important for Rubio and Kasich, certainly, but important. After today, there are going to be barely 1,000 delegates on the table and if Cruz doesn't get any of the delegates from either Ohio or Florida, he needs a really good haul from the other three states in order to give him a path to 1,237 that is plausible. Cruz does not want to go into a contested convention and put his fate in the hands of the Republican delegates any more than Trump does.

He also needs - desperately - to continue the narrative that he is able to beat Trump on a regular basis. Cruz's detractors like to say that he has already shot all the best bullets in his gun and that he can't win outside a narrow kind of state - winning in any of the other three states up for grabs would dent that narrative, reinforce the idea that Trump is still vulnerable, and keep the race headed in Cruz's direction.

So tomorrow isn't a must-win, technically, for Cruz, but you can believe that his team desperately wants to put at least one in the win column.

This election has been depressing in a whole lot of ways, but on the other hand, it's exciting that so much is up in the air on March 15th. All the candidates have so much on the line, this could be the biggest day in the whole election season; even bigger than Super Tuesday.