In an interview with Chuck Todd that will air on Meet the Press Sunday, Speaker of the House Paul Ryan says this:

"The last thing I would do is tell anybody to do something that's contrary to their conscience. Of course I wouldn't do that. Look, believe me, Chuck. I get that this is a very strange situation. He's a very unique nominee. But I feel as a responsibility institutionally as the Speaker of the House that I should not be leading some chasm in the middle of our party. Because you know what I know that'll do? That'll definitely knock us out of the White House."

Ryan is, I believe, conscientiously trying to do the right thing. But in continuing to support and excuse Trump—even while allowing his members to follow their conscience—he's not. And one problem is Ryan's mistaken understanding of his institutional responsibility. He's thinking as if he's the Republican leader of the House, whose task is to hold the party together and to help a Republican win the White House. But Ryan isn't merely the Republican leader. He's not the majority leader of the House. He's the speaker. That's a constitutional office. His obligation is to the country, not just or mainly to the party.

This doesn't mean Ryan has to oppose Trump or join in efforts to deny him the nomination or find an independent candidate. But it does mean Ryan can, as speaker of the House, withdraw his endorsement of Trump and say he's going to focus on the House's business for the rest of this session. It does mean Ryan can say, as the senior Republican in the House, that he'll focus his electoral efforts on helping get his colleagues reelected so as to retain a Republican House. It does not mean he needs to continue on an untenable path of supporting Donald Trump.

And if his House colleagues want a speaker who'll subordinate his judgment to Trump's, Ryan can give them an opportunity to tell him that. He could even offer to step down as speaker if the conference wishes. I can't believe his colleagues would actually take him up on that offer. To the contrary, an increasing number of them would welcome the distance that would be created in Ryan liberated himself from Trump. For there is no compelling reason for Speaker Ryan to tie himself—or his colleagues—to Donald Trump. And there are an increasing number of reasons for him not to.