That puts me in complete agreement with my friend Amy Walter of the Cook Political Report, who observed that “by the time we hit the summer of 2020, the issue of impeachment will just be one more in a string of unprecedented, presidency-altering events that have come and gone in the mind of voters.”

Some Democratic incumbents in pro-Trump and Republican states and districts will lose their seats next year, but they probably would have lost them even if their party had not pursued impeachment. But many Democrats in swing seats who were first elected in 2018 because of voters’ animosity toward Trump should not find themselves in difficulty next year primarily because they supported impeachment.

The disruption and chaos that Trump brought to the presidency, and to our politics, has resulted in more anger and name-calling, additional partisan polarization and a growing sense that the 2020 election will be crucial to the country’s future, no matter which side you are on. But it also means that the battle lines for 2020 have already been formed, and both sides have more than enough ammunition.