Impeachment of Trump, even assuming it is possible, would pave the way for a clean Republican victory in 2020. Under a replacement leader (Pence?) the Republican party would quickly consolidate, no longer embarrassed or frustrated by a loose cannon at the helm and voters give most incumbent presidents a second term. Meanwhile, the Democrat Party would stay divided.
Though it would be nice to see Trump brought down by legal process, it’s probably better that he fries himself and his party all the way to the finish line. Though our greatest fear is that they may fry the planet along the way.