By all accounts, Ted Cruz had a great day on Saturday, scoring surprise wins over Trump in Kansas and Maine (by fairly comfortable margins), tying him in Louisiana, and narrowly losing Kentucky. Cruz narrowly closed the delegate gap with Trump and just as importantly increased the space between himself and the other non-Trump candidates.
Today, Ted Cruz needs to do three things in order to keep his momentum going, in no particular order.
1. Beat Marco Rubio (and John Kasich) in Michigan. Donald Trump is probably going to win Michigan. Cruz's strategy in Michigan is to beat two guys who have been saying for months that Michigan is the sort of state they would both do better in than Cruz: Marco Rubio and John Kasich. The knock on Cruz has always been that after Super Tuesday, the map shifts to more non-evangelical, non-conservative states. Rubio and Kasich have been saying all along that they would beat Cruz in states like Michigan. If Cruz beats them both, he scores a convincing win for his narrative that he is the best anti-Trump candidate across the board. Of course, in Kasich's case, it might not matter, since Kasich is a deluded fool, but to some of Kasich's voters, it might. And it definitely will to Rubio voters.
2. Win Idaho. No one knows what is going on in Idaho, but Cruz has been campaigning hard there with the expectation of a win. In fact, Cruz gave his victory speech on Saturday from a rally in Cour d'Alene. Idaho is a primary, but it is closed. Cruz needs at least one outright win today to keep the narrative "I am able to consistently beat Donald Trump" going, and Idaho is probably his best shot. Idaho's a small state, but there's important symbolic value in adding outright state wins to the tally.
3. Win (or effectively tie) Mississippi. As much as Cruz will not admit it, the loss of several deep South states stung his chances against Donald Trump in a serious way. The worst losses of his campaign were the shellackings he took in Tennessee, Alabama, and Georgia. The collapse of Rubio allowed Cruz to turn that around in Louisiana and Kentucky to draw very close to Trump. It would be an enormous feather in Cruz's cap if he could claim an outright win in the Deep South. Probably, he wants this to happen worse than anything today, although it is the least likely thing to happen. At the very least, he needs to claim a delegate tie (or close to it) like he got in Louisiana.
Wild Card: Hawaii. Who even has the vaguest clue what is going to happen in Hawaii? I sort of assume Trump is going to win because it's a pretty liberal state but I assumed the same thing about Maine. Maybe Cruz wins? Maybe Kasich wins? Maybe Reagan's corpse wins? I think if Cruz is even close to Trump in Hawaii he gets to claim another win.