A possible, and not unlikely outcome, for tonight is this: Trump does about as well as is expected, Cruz wins Texas, and Rubio outperforms Cruz in the other states but without winning any of them. The anti-Trump elements – which is to say, conservatives who have not taken leave of their senses – will desperately want their second- and third-favorite candidates to exit the race, so that the anti-Trump vote can coalescence around one non-Trump candidate.
But if things shake out as expected, there won’t be a very strong case for anybody to get out of the race except for the two guys who don’t really have much business still being in to start with.