The Daily Beast points out:

Speaker Ryan to Trump: STFU

[…]

Still, many rank-and-file lawmakers on Capitol Hill are terrified of Trump and won’t dare cross him, lest their constituents pledge allegiance to Trump over a Republican incumbent. “I’ll wait to see what happens, nothing’s happened yet,” Rep. Pat Meehan (R-PA) told The Daily Beast when asked if he could support Trump.

Trump has now secured the endorsements from five sitting members of Congress, which analysts predict will grow as he continues to pick up delegates leading into the convention.

[…]

That anger is on display across the nation today as voters are expected to come out in droves largely to support Trump. When asked if the GOP is on the brink of destruction, Ryan demurred.

“I never believe that our party is beyond the point of repair, but of course we don’t want to see division within our parties. We are conservatives, we believe in the American idea,” Ryan said before adding that he will throw his support behind Trump—even with his quiet endorsement of racism, xenophobia, and sexism—if Republican voters pick him. “I plan to support the nominee. I think I’ve said enough this morning about what’s happening right now—but my plan is to support the nominee.”

“Conservative” ninnery will only help Trump. Trump is just taking advantage of their group-think.