Republicans will need to gain 18 seats to win back the majority (or 19 depending on the outcome of a new election in NC-09), and have no shortage of good-looking targets, at least on paper: there are now 31 Democrats sitting in districts carried by President Trump in 2016 and just three Republicans sitting in districts carried by Hillary Clinton.

But Democrats have history on their side: the House majority hasn’t flipped twice in a row since 1954 and hasn’t flipped during a presidential cycle since 1952. Democrats have gained House seats in five of the past six presidential elections (save for 2004, when Republicans drew a favorable new map in Texas) and in seven of the past eight presidential cycles, the net partisan seat shift in the House has been in the single digits.

Earlier in the decade, we theorized that for Democrats to win back the House, they would need either a resettlement program to move more of their voters into competitive districts or an unpopular GOP president in a midterm year. In 2018, they got the latter. Now, it’s tough to see Republicans winning the House back unless President Trump’s approval rating is significantly higher than today’s 42 percent come 2020.