There is so much turmoil in Washington right now that it seems necessary to get down to essentials.
The most essential for holders of federal office is the U.S. Constitution that they have all sworn to uphold, to "support and defend." Some offences committed by the current regime are in the Constitution itself. Others are violations of law that flesh out Constitutional mandates. Moreover, they are laws passed as prescribed in the Constitution. That's what makes them lawful.
The Constitution sets forth responsibilities. The Justice Department has responsibilities to uphold the law regardless of whether transgressors are in high office and in the same party, including the guy who hired you. The FBI has investigative responsibilities, and answers to both the Executive and Legislative branches.
Members of Congress swear that oath to the Constitution. Notably they have to sign it as well as say it. They have the ultimate responsibility to uphold the Constitution when the Executive violates it.
Unfortunately most of them won't do so unless they perceive that the political zeitgeist forces them to. So the media furor, the polls and the heat members of Congress get at "town hall meetings" in their districts and states, etc. all play a part.
The essential crime is violating the Constitution. The essential remedy is following the Constitution, regardless of party or politics.
So ladies and gentlemen, do your fucking jobs. Until that happens it's all just a sordid circus.
And ultimately, if you don't do your jobs, darkness falls all the faster.