Now they are back to impeachment as a campaign issue.
Because it was such a great issue the first time around. Almost as good as the "Russian collusion" issue. Or the "Stormy" issue. Or the "tax cuts for the rich" issue. Even better than the "misogynist" issue.
Let's face it, the Democrats campaign issue in 2018 might as well be "MAMA". As in "Make America Mexican Again". It would probably poll well in the elitist regions on the coasts, and who cares about the small groups of deplorables in flyover country.