I think they pissed off enough Americans with their antics as it is. Great, give people another reason to keep Democrats out of power. Preach it loud and wide.
I think you're right. Every time I hear or read about one of the whiney Dems calling for impeachment and/or investigations it makes them look bad to everybody outside of their base. Is it going to increase the turnout in their base and much as it'll cost them with everybody else? Doubtful IMHO.
I think the past several years they have driven more people to the right. Trump won, the next day, impeach Trump. Kavanaugh nominated, the next day, impeach Kavanaugh.
The Constitution says Congress can impeach on charges of high crime and misdemeanors. The Democrats are telling people "To hell with the Constitution. We are impeaching because we don't like them!"
They are virtually trying to overthrow our government. That's why smart Americans will keep them as far out of power as possible before they start another civil war in this country.