As I said in another thread, I'm 99% sure that Trump will be the nominee, but I can't help spending 50% of my time talking about the 1% chance he doesn't.
We've talked about what scenarios would be needed for X candidate to beat Trump, what I think it's really down to is the scenario that would make Trump NOT win, and nobody else either.
To use a football anology, it's like week 15 of the regular season and for the Bears to make the playoffs, they need the Lions to beat the Packers and the Bengals to beat the Cowboys with the 49ers/Rams game ending in a tie.
There isn't a non-trump republican candidate left who controls their own destiny, imo. Cruz "needs" Rubio to win Florida and/or Georgia, or pull delegates from Trump. Kasich winning Ohio and/or Michigan would help Rubio and/or Cruz. Cruz winning Texas helps Cruz the most, but also helps the others by keeping Trump from claiming the crown too quickly. We're down to a war of attrition while the GOP hopes and prays to discover nukes in time. or whatever.