Since the 1930s, one of the most dependable regularities in American politics has been midterm loss, a swing against the party of the incumbent president. Whether due to a reaction to the sitting president’s agenda or to voters seeking a counterweight to the president, the party not holding the presidency has made gains in the House in the midterm elections in every election but two since 1934.

And one of those elections where the president's party saw gains in a midterm election? 2002, almost certainly because of Bush II solidarity post-9/11.

Now, the Democrats face a shitty Senate reelection map going into 2018. Consensus is that they are hankering for a potential flip their way in two states (AZ and NV) and pray to Jesus they can ward off challengers to 10 (D) seats in states that both Romney and Trump carried.

Still nursing their wounds after last week’s thrashing, Democrats already are grappling with how to defend 10 senators up for reelection in 2018 in states that Donald Trump carried, some resoundingly. Republicans are targeting a quintet of senators from conservative states where Trump walloped Hillary Clinton: Montana, Missouri, Indiana, North Dakota and West Virginia. The GOP could amass a filibuster-proof majority by running the table in those states and other battlegrounds.

So while the midterm election swing away from the party of the president is one of the most reliable features of American politics, the reelection map is not to their favor. It's all up to Trump. I'm still getting used to that sentence.