Beto O’Rourke should run for the Senate. In another state. If Trump gets re-elected.

A number of people (including a longtime friend) have said that Beto O’Rourke should end his bid for president and focus on running for the Senate.

This idea is borne of a few things, notably the perceived lack of great challengers to Republicans and the perceived surplus of presidential candidates. (Texas Sen. John Cornyn has some good challengers.)

But running for the Senate isn’t just some thing you should do if you’re not cut out for running for president. Most people who run for the Senate lose. So how certain can we be that Beto would lose if he ran against either Cornyn next year or Cruz again in 2024?

I looked at every regular Senate election dating back to 1952 (except 1968’s, and more on that soon). I categorized them as:

1. Incumbent president (IP) up for re-election.
2. IP term-limited.
3. IP’s first midterm.
4. IP’s second midterm.

Since 1968 was none of those, and since 1968 was a bit of a special year, I didn’t include it as its own data set.

Of the four circumstances, the incumbent president’s second midterm involves by far the most bloodletting. Challengers to incumbent senators who are members of the president’s party — as Cruz and Cornyn are — win 36 percent of the time when they run in the president’s second midterms. Here’s a chart of the four scenarios:

Beto already ran for the Senate in the incumbent president’s first midterm (which is the worst way to challenge an incumbent) and lost. His next chance will come next year, but his best shot — second midterm — would require that Trump win in 2020. And he’d have to move: Neither of Texas’ senators will be up for re-election in that year.

In fact, Beto’s best shot at winning a Senate seat is to find a winnable race in another state with an incumbent who is retiring and watch as Trump wins in 2020. Pennsylvania and Wisconsin are probably his best carpetbagging options, and if he can help turn either state blue even as Trump wins the Electoral College, he might have a shot.

Now, why does the senator’s incumbent status matter? Here are the odds for a major party senate nominee beating a senate nominee (as opposed to incumbent) who is a member of the party controlling the White House:

What’s up with the high win rate for challengers in the president’s second midterm, anyway? Probably the lack of protection from the president. A senator who’s up for re-election six years into the president’s total time in the White House was elected when that president was elected. Without that president at the top of the ballot — and with the country’s concerns having changed — it’s easy enough to see the electorate going in a different direction.