Consider, of the three competitive races that Obama re-emerged from (quasi) private life to try and whip, all three lost.

Andrew Gillum, Sen. Bill Nelson, and Stacey Abrams were all supposed to be in unbelievably tight races. In the end, they all finished behind their Republican opponents (Abrams could still just barely make a runoff, but it doesn’t look good) despite Obama taking the time to rally for them.

On the one hand, this may just reflect poor selection of candidates, though that demonstrates his efficacy as a whip as well. But on the other, Obama fell into the trap of being Obama in the era of Trump.