As Nancy Pelosi and House Democrats weigh the potential electoral risks of beginning impeachment proceedings, they must also consider the risks of not doing so.
Demonstrators from the pro-impeachment group By the People rally in the Cannon House Office Building Rotunda on Capitol Hill on May 14th, 2019, in Washington, D.C.
A woman holds a sign during a press conference where activists delivered a computer flash drive with 10 million signatures calling for the impeachment of President Donald Trump.
As Democrats weigh the benefits of impeachment following the release of the Mueller report, here's what history says about the arguments for or against proceeding.