Control of the House still hasn't been decided- it could still swing to the Democrats narrowly- and my reference point for landslides in U.S. presidential politics is the Democratic landslides in 1936- 61% , 46 out of 48 states- and 1964- 61.1%, 45 out of 50 states- and the Nixon-60% 49 states- and Reagan- 59% and 49 states- GOP landslides.

Agreed that the Democrats underperformed badly, but Trump doesn't have that much to gloat about.