(Manuel Balce Ceneta/AP)
Opinion writer

Some Democrats have begun to worry that if President Trump loses reelection next year, he might refuse to give up power. House Speaker Nancy Pelosi (D-Calif.) warned in an interview published over the weekend that the Democrat will need a landslide victory to keep Trump from refusing to leave office.

Given that Trump himself is feeding this idea — he’s now saying that he had the first two years of his presidency “stolen” from him by the Russia investigation — this is not an unreasonable worry.

But in a sense, Democrats are actually worried about the wrong threat. The real threat is a related one, but it concerns the whole Republican Party, and not just Trump.

It’s that the next Democratic president could face an opposition party that acts as though the president has no legitimacy whatsoever. And I fear that Democrats, with their focus on Trump, are not taking this threat seriously enough.

You see this blind spot among many of the 2020 candidates. Sen. Bernie Sanders (I-Vt.) doesn’t see any need to get rid of the legislative filibuster if he becomes president, in the apparent belief that some Republicans will support his agenda.

Meanwhile, Joe Biden believes that Trump is but a strange historical anomaly we just need to get past, and then the GOP will return to sanity. “This is not the Republican Party,” he told a crowd in Iowa, testifying to the good will of “my Republican friends in the House and Senate.”

Someone might remind Biden that in 2009, when he was vice president, Republicans decided to oppose President Barack Obama on anything and everything he wanted to do. Someone might also remind Biden of that time when Mitch McConnell simply refused to have the Senate even consider the nomination of Merrick Garland to the Supreme Court, by making up a new “rule” that presidents don’t get to nominate justices in the last year of their terms.

Most importantly, just about every Republican senator supported McConnell’s unprecedented move. They argued that the court could operate just fine with eight judges, so we should just wait for the next election to fill the seat.

If Republicans retain the Senate in 2020, what’s to stop them from saying that they won’t consider any more nominees for the Supreme Court until there’s another Republican in the White House, because the court can do fine with eight or seven or six justices?

If your answer to that question is that Republicans would never go that far, you haven’t been living on this planet for the past decade or two. That’s who they were before Trump was elected.

Trump has merely taken this to new heights, and in so doing, is pushing the overall GOP further along in this direction. For the entirety of his term, he has encouraged the Republican base to hold every institution of American democracy — the press, the courts, the Constitution — in utter and complete contempt. The message over and over again is that the only question is whether institutions are doing what you agree with, and if they aren’t, then they have no legitimate role to play in our system.

Most recently, the White House is acting as though the constitutional powers granted to Congress are meaningless. The law says Congress can demand anyone’s tax returns? Sorry, we refuse. Congressional subpoenas? No, we don’t think we’ll comply. Testimony from administration officials? Go to hell.

But even if Trump does lose reelection, the GOP is likely to continue with this — and make it a lot worse.

Imagine it’s 2021. A Democrat has won the White House, but Republicans control the Senate. The Democrat doesn’t just get no Supreme Court judges, she gets no judges at all; those seats can just stay vacant. Cabinet confirmations? Sorry, we’re not going to let a bunch of socialists govern. As Eric Levitz recently wrote, “do you really think Senate Republicans are going to help President Elizabeth Warren install her preferred leaders atop the Treasury or SEC?”

They will surmise, and not without reason, that there is virtually no limit to the amount of sand they can throw in the gears of government without worrying about political blowback. They don’t care whether government works, so what does it matter to them if anyone is in place to run it? Their attention will immediately focus on getting their own voters out for the 2022 election.

Meanwhile, the defeated Trump will be on Fox News and Twitter every day saying that the election was stolen from him and that the Democrat is not really the president. And the GOP base, having learned well in recent years that no Democrat can ever be legitimate, will stand behind the GOP’s obstruction.

I wish I had a clear and simple plan I could recommend to Democrats to forestall that possibility. But there is really only one way to do it: Win. Deprive Republicans of all levers of power. Because if the GOP has any ability to make governing impossible for the next Democratic president, it will. Count on it.