At this point there's a calculation going on in every House Republican's mind, as to whether coming to Trump's defense is preferable to "President Pence".
Today in a speech to Coast Guard Academy graduates, Trump took time from celebrating their achievements to whine that he was "No other president in history has been treated so unfairly" Y'know, aside from the last one being accused of not being an American citizen, Bill Clinton being accused of orchestrating murders while governor of Arkansas, Lincoln, Kennedy, Garfield and McKinley being assassinated. Aside from THAT.
Make no mistake, Trump dug this hole he's in himself. He has constantly contradicted his own staff as they tried to work damage control, he started his presidency by insisting that his inauguration was the largest crowd in history when it demonstrably was proven otherwise, he has belittled legitimate news organizations whenever they dared not fawn over the rightness of his decisions, and he's used up any political good will he might have had in Congress by the abrupt firing of Director Comey, by carelessly giving out information to the Russian ambassador, and by apparently attempting to obstruct justice by earlier demanding Comey drop his investigation of Mike Flynn.
I predict, rather than put up with inevitable public disgrace that will come with Mueller laying out all of Trump's actions and lies for the world to see, that Trump will resign as soon as he has assurance from Pence that his actions will be pardoned. I doubt he'll be president by the end of summer. It's quite possible he won't be president by the end of this month.