Donald Trump has won Michigan and Mississippi this evening. Hillary Clinton has so far apparently earned a split of those two states with Sanders.
Kasich and Rubio combined in Mississippi garnered less than 15% of the vote, less than 36%. They need to get out of the race. The only purpose they can serve now is to win their own states and forestall Trump and possibly force a brokered convention. If they can actually win their home states. It's becoming highly questionable that they can. And if they are successful, they might actually bring down the Republican party with a brokered convention. Ted Cruz, despite having a bad day, is the only real other alternative at this point.
Hillary Clinton meanwhile is struggling with Bernie Sanders. She's appearing more and more to be a weak candidate for the general election, just like Trump.
This is bizarro world.