Obama's refusing to enforce immigration laws with two illegal amnesties, thus encouraging an invasion, was done for the good of the Democratic party, not the country. That was worthy of impeachment.
As a practical matter, impeachment does not accomplish much, since the 2/3 supermajority in the Senate is a high bar, since an impeached president is replaced by a VP who will pursue the same policies, and since impeachment energizes the party of the impeached president.
Who wants to be the next Democrat president with a Republican congress?
Clinton was guilty of felonies...perjury and trying to get other people to commit perjury on his behalf.
Watergate started with something trivial (an unauthorized wiretapping for political purposes...probably most recent Presidents had done similar things), but they cornered Nixon on "process crimes."
The Democrats have cheapened impeachment.