I hate to use this example given how the show ended, but i think it's accurate and the show was still good when this part happened....So, anyhow....What we are seeing with the democrats is like what happened when Cersei Lannister decided her path to regain power was to back a religious cult.
The democrats were desperate to regain the power they had lost, but had nothing anyone wanted. They needed something to match the energy of Trump supporters. So when they saw the raw passion of a bunch of nut jobs on the fringe of their party they said hey lets push those wackos front and center then we'll co-opt their movement then ride the wave on in to victory.
Only like Cersei the democrats didn't believe in or care about anything other than the power they think they are owed, so they failed to recognize the group they were empowering were batshit nuts and there was zero chance they going to be controlled. Now in stead of co-opting the radicals the radicals have co-opted them and the democrat party is collectively locked in cell with their heads shaved waiting to confess their sins to the High Sparrow then take their walks of atonement if they can convince him they're crazy now too.
...Seriously what is the plan to impeach a President on the back of secret impeachment hearings other than a plan to blow up the whole government in the hope you come out on top when the smoke clears. Makes you wonder could Nancy Pelosi have been George R. R. Martin inspiration for Cersei Lannister :)