Oh shít:
As for @AdelaideCate007's question: It is very unlikely Trump will be convicted in the Senate and removed, which is controlled by the Republican Party. It is very likely the House will move to impeach, though, which is a major blow. The only way Pence (who is indeed up to his neck in this) would take the White House is if Trump were convicted and removed. As of now, impeachment is simply a smart political and moral stance going into an election year.
The difference with Nixon is, there a bipartisan group of Senators from both parties were prepared to convict him. The GOP of the '70s was not as fanatical and corrupt as it is now, and they found Nixon's crimes beyond the pale. Nixon knew they would vote against him and resigned to avoid that conviction. Today's GOP will countenance any crimes for power.