If you've ever played three-dimensional chess, you have some notion of what Paul Ryan is dealing with in his political game with Donald Trump.
Except that Ryan's dilemma has more than just three dimensions.
On the first level, Speaker of the House Paul Ryan is the highest federal officeholder in the Republican Party. In this role, he is slated to be the chairman of the party's national convention in July. And in both roles, it is presumed he will back the party's nominee for president.