“I don’t get it,” President Trump said at a recent White House meeting, according to Politico. “All these other Republicans, all over the country, they all win their races. And I’m the only guy that loses?”
The premise of the president’s question was wrong. Senate Republican candidates and Trump ran within a few points of each other in most states, and there was only one state in the country where a Republican Senate candidate won and Trump lost (Maine).
As for the House? The Cook Political Report points out that there was a pretty even split between the number of Biden/House GOP congressional districts and Trump/House Democrat districts — and the number of split districts in 2020 likely marked an all-time low.
Based on a variety of number-crunching sources, it looks like there were at most 16 districts out of 435 that split their tickets between president/House in '20 - likely an all-time low. For perspective, there were 83 such districts in '08 and 35 in '16.
Biden/R districts (9):
#TX24 Van Duyne
Trump/D districts (7/8?):
#NY22 Brindisi (?)
The fact that Republicans picked up House seats even while Trump lost reelection has been confusing to Trump and some of his supporters, but the reason that happened is simple. In 2018, House GOP candidates trailed nationwide to House Democratic candidates by 8.4 percentage points; Republicans lost their majority and ended up with 199 seats. In 2020, House GOP candidates only trailed House Democratic candidates nationwide by 3.1 points, and they’ll hold 211 to 213 House seats in the next Congress.
The 2020 performance of House Republicans greatly beat expectations, but that performance is consistent with an election in which President Trump lost the national popular vote by 4.3 points.