Surprising almost no one, Rep. Darrell Issa (R-Calif.) announced Wednesday that he wouldn't be running for re-election. Issa, known to most people for his entertainingly bumbling turn as chairman of the House Oversight Committee during the Obama years, is one more wildebeest in the midst of a Republican stampede, dashing headlong for the exits. He followed his fellow Californian Rep. Ed Royce (R), who announced this week that he's giving up his chairmanship of the Foreign Affairs Committee and saying goodbye. And there are more to come.

The number of Republican incumbents in the House calling it quits has now surged past 30, more at this stage of the cycle than in any recent election. It isn't hard to see why, since everyone is predicting an enormous Democratic wave that sweeps over every competitive race, and a few we didn't realize would be competitive. If you're looking at a tight race like Issa was — he won re-election in 2016 by a mere 1,621 votes — you're probably asking yourself whether you're doomed and there's no point bothering to run again. That's the thing about wave elections: They sweep away all local concerns and the ability of an individual candidate to stop it, as voters just cry their displeasure in the voting booth with little regard to who's on the ballot.

But if anyone can survive that kind of wave, it's a well-known incumbent. That's why retirements are so important: They make it much easier for the other party to pick up seats, potentially making the wave even bigger. And there's another key reason so many Republicans are retiring. It's not because they're afraid they'll lose, but because they're afraid of what would happen if they won, but their party lost control.

Imagine for a moment that you're a Republican member of the House. You've been in the majority since the 2010 sweep, long enough to get used to it. Your party controls the committees and the floor. You seldom have to take a tough vote, or have to endure hearings on uncomfortable subjects. You've got influence, and if you're high-ranking enough, real power.

Now imagine all that being snatched away in November. You have to understand how different the House is from the Senate, and not just because there are 4.35 times as many members. The Senate has all kinds of rules that give each individual senator prerogatives and power, because that's how senators of both parties like it. Even when you're in the minority, you're an important personage. But being in the minority in the House sucks. It's a total drag. You spend a lot of time complaining about how you're being mistreated by the majority, and besides that you barely have anything to do besides answer your constituents' complaints, send out fruitless press releases, and plot what you'll do if you're fortunate enough to get back in charge.

And it will be particularly bad for Republicans in the next few years if Democrats take back control. First you'll endure two nightmarish years of Democratic investigations of the Trump administration as the opposition uses its newfound subpoena power to the fullest. With the Republican legislative agenda ground to a halt, you'll constantly be pestered to respond to the latest administration scandal or crisis. It's been bad enough up until now, but at least you could say to the endless queries, "I'm not concerned with the president's tweets, because I'm focused on our legislative agenda." If the Democrats are in charge, you'll have no legislative agenda.

Then if a Democratic presidential candidate wins in 2020 — which is a strong possibility with President Trump's approval ratings in the 30s even when the economy is strong — it'll only get worse. Come January 2021, you could have to sit back and watch as Democrats roll over you to enact their Euro-weenie agenda of tax increases, enviro-extremism, and socialized medicine. Will you be able to stop them from forcing our children to bake cakes for abortionist gay marriages? Probably not.

The mere thought is enough to send a congressman running to the waiting arms of a K Street lobbying firm, where at last he'll be properly remunerated for his unique talents. And there's a feedback loop: The more GOP incumbents opt to retire, the better the chances of Democrats taking over become, and the more attractive retirement looks for the members who remain.

There's no way to know how high the number of retirements will get, but it wouldn't be shocking to see it pass 40 or even 50. In the future, Republicans may look back and say that their congressional majority is just one more thing Trump ruined.