It's only a question of how long it takes for Jeb Bush to decide that he will not win this election. He did badly in a New England state (IA), a new England state (NH), a Southern state (SC) and a far-western state (NV). He has no regional strengths that he can exploit. Ben Carson has become a political joke.
Kasich has a chance if he does extremely well in regions of America in which the Republicans are better educated (the Northeast, Midwest, and Pacific Coast regions), so I really can't rule him out yet. He might get more of a crossover vote in November -- but for him, just about everything must go right.
Jeb dropped out last night