Washington Post reporter Dave Weigel tweets:

Okay, but isn’t it possible that a candidate who could have beaten the 2016 Trump wouldn’t beat the 2020 Trump? Leave aside the question of whether national conditions will be helping President Trump win reelection.

The mere fact that he will (presumably!) be President Trump will give him a boost. Only three presidents have lost reelection* in the last century, and all three of the last presidents won reelection. The power of incumbency shouldn’t be underestimated.

*As @incitatus17 pointed out to me, I forgot Gerald Ford, who lost “re”-election. He also points out that only once in the last century has the country switched parties twice in a row in presidential elections.