Mueller's investigation was supposed to be about Russian collusion and look how far it has expanded. Everyone, Democrats and Republicans alike should be very afraid as to the direction all these agencies have taken.
Lastly, if Trump does do an impeachable offense, which he hasn't, President Pence will take over and at that point, good luck to you Democrats because the guy is extremely conservative and clean as a whistle. In other words, be careful what you wish for!