I will say at the outset, that I think these strategies remain real long shots. I fully expect Trump to collect enough delegates to have a majority at the convention. Still, the strategy to stop him from obtaining a majority at the convention is possible and realistic, even if difficult.
Cruz will continue to make this a two person race between himself and Trump. Cruz will ignore or belittle Kasich in most places. The line will be that Kasich won his home state and nothing else. If he cannot win any other State, he is not a serious contender, even if he picks up a few second or third place delegate here or there. The next two primaries, next Tue. March 22 are closed primaries in very conservative States: Arizona and Utah. These should be places where Cruz should have a shot at challenging Trump, although Trump is probably favored to win both. Arizona is winner take all, while Utah is proportional. Watch to see if Cruz presses hard in Arizona. If he does, that tells us his internal polling shows he has a chance at a win there. Otherwise, he will focus more on Utah to squeeze as many delegates as possible.
Kasich wants to collect all the folks who dislike Trump and Cruz. There are lots of them, but the next two contests will probably not have much for him. Kasich may try to pick up some delegates in Utah, but will likely look past these States.
After Arizona and Utah, the map turns more in Kasich's favor. Wisconsin has an open primary on April 5 which is winner take all. This will be a test of whether Kasich can win anything outside of Ohio. It is a midwest state which should be open to his message. If Trump defeats Kasich in Wisconsin like he did in Michigan, then Kasich again has to consider whether going home is the best thing he can do.
After Wisconsin, Kasich can look forward to a number of other moderate states: New York, Connecticut, Delaware, Maryland, Pennsylvania, and Rhode Island. These are not strong states for Cruz. Kasich needs to be able to pull a few of them away from Trump in order to prevent an end to the primary fight. If Trump can do well in these States, as polls show, he will get a majority. The later States in May and June become irrelevant. If Kasich can start taking even a few states, the fight goes on.
At present, Trump has 673 delegates, with 1237 needed, 564 more. Here are the remaining Republican primaries:
- Tue, Mar 22 Arizona 58 (WTA) Closed
- Tue, Mar 22 Utah 40 (P) Closed
- Tue, Apr 5 Wisconsin 42 (WTA) Open
- Tue, Apr 19 New York 95 (P) Closed
- Tue, Apr 26 Connecticut 28 (P) Closed
- Tue, Apr 26 Delaware 16 (WTA) Closed
- Tue, Apr 26 Maryland 38 (WTA) Closed
- Tue, Apr 26 Pennsylvania 71 (P, WTA) Closed
- Tue, Apr 26 Rhode Island 19 (P) Mixed
- Tue, May 3 Indiana 57 (WTA) Open
- Tue, May 10 Nebraska 36 Closed
- Tue, May 10 West Virginia 37 Mixed
- Tue, May 17 Oregon 28 (P) Closed
- Tue, May 24 Washington (R) 44 (P) Closed
- Tue, Jun 7 California 172 (P) Mixed
- Tue, Jun 7 Montana 27 (WTA) Open
- Tue, Jun 7 New Jersey 51 (WTA) Closed
- Tue, Jun 7 New Mexico 24 (P) Closed
- Tue, Jun 7 South Dakota 29 (WTA)
Let's say Trump wins all the winner take all, and takes about half of the proportional. That would give him just about enough to win an outright majority of delegates, with maybe 50 or so to spare.. If Cruz or Rubio can win two or three of the winner take all states, and keep Trump's average at or below 50% of delegates in the proportional, there could possibly be a divided convention.
That is not an impossible scenario. Trump has only broken 50% once, and that was in the tiny Northern Mariana Islands caucus. If Trump has a hard ceiling of 45% and cannot win all the winner take all states, he has a serious problem getting 50% of the delegates. Some of the states still keep a few delegates uncommitted or award some based on Congressional district wins, meaning Trump may not win "all" in a winner take all state. Even with all of his big wins so far, Trump has only collected just under 48% of the delegates awarded. Impressive in a race with lots of candidates, but not enough to get that outright majority.
It will be interesting to see how the voter dynamic changes with Rubio out of the race. Kasich will now get a much closer look by the electorate and also come under closer scrutiny and criticism. He could step up and gain momentum, or he could whither under the spotlight as so many have done before.