House Democrats already submitted for vote a resolution to impeach the president a few months after he was initially rightfully elected. It failed. A number of Democrats voted against it, I believe including Pelosi.
https://en.wikipedia.org/wiki/Effort...h_Donald_Trump
On January 19, 2018, Green brought up the resolution a second time. On this attempt his motion was defeated by a vote of 355–66. 234 Republicans and 121 Democrats voted against the motion. All the votes for the motion were from Democrats: three Democrats voted present and three Republicans and three Democrats did not cast a vote