President Trump. (Evan Vucci/AP)
Opinion writer

If you’re a Republican in a competitive district — or even one that wasn’t really supposed to be competitive — you may be asking when President Trump is going to stop making your life so much more difficult. You loved the tax cut, of course, but while it accomplished the profound moral good of helping large corporations buy back billions of dollars in stock, the voters stubbornly refuse to say they’ve been helped by it. And now things are going off the rails. It’s almost as if the president doesn’t want Republicans to hold on to Congress.

First there’s the administration’s new “zero tolerance” policy with regard to people crossing the border, which has now separated thousands of children from their parents. Even apart from the moral outrage, it has become such a political disaster that Republicans are actually standing up to Trump and opposing it, something most of them probably never imagined they’d do.

Meanwhile, Trump is going ahead with his trade war, on Monday threatening, as The Post reported, “to levy tariffs on nearly all of China’s products shipped to the United States unless Beijing agrees to a host of sweeping trade concessions, a dramatic escalation that would enlist American consumers in the brewing U.S.-China commercial conflict.” In case it’s not clear, “enlist American consumers” means “make you pay more for a whole lot of consumer goods.” Naturally, China is threatening retaliation, which would harm U.S. exports.

While Trump may believe that “trade wars are good, and easy to win,” the thing about a trade war is that it imposes short-term pain not just on the other country but also on your own, for the promise of long-term gain. The hope is that the other side will find the pain intolerable before we do, and give in to Trump’s demands.

I don’t profess to know whether that will or won’t happen with regard to China, or the other countries, such as Canada, that Trump is targeting as other fronts in his trade war. But if Trump actually follows through, we’re going to have to go through the suffering phase before we get to the glorious victory phase. Which makes it unlikely that voters are going to be cheering Trump’s clever and effective economic policies.

One thing we can say for sure: Even if he thinks they will eventually help him and his party politically, Trump is pursuing a trade war and family separation because he believes in them. Immigration and trade are two of the only issues on which he has long-standing, consistent positions. And both could endanger the party’s standing with moderate voters.

Which is what Republicans are afraid of. As I wrote earlier Tuesday, their skittishness around the Trump administration’s family separation policy may be partly a result of sincere moral revulsion, but it is most certainly fed by an evident fear of how voters are going to react. Republicans’ biggest problem, however, is likely not moderate voters but Democratic ones. And Trump seems determined to keep those Democrats as angry as possible and as motivated as possible to get out and vote.

There’s anger on the Republican side, too, but it seems to be manifesting itself in ways destined to undermine them, particularly in the election of GOP nominees who are guaranteed to increase Democratic turnout. For instance, in New Jersey, where Democrats think they have a chance to sweep all five of the districts currently held by Republicans, the state GOP is distancing itself from Seth Grossman, its own nominee in one race, after he said diversity is “a bunch of crap.” In Virginia, the party is in a panic over Corey Stewart, the Confederacy fanboy who won its nomination to challenge Sen. Tim Kaine.

The real problem isn’t so much that candidates such as Grossman or Stewart will lose, which they probably would have anyway. The problem is that their extremism not only garners lots of media attention but also feeds right into the things that are motivating Democratic voters to get to the polls. That’s why, for instance, the person most terrified of Stewart is Barbara Comstock, who represents a Northern Virginia district in the D.C. suburbs.

Comstock was already one of the most vulnerable Republicans in the country, and though she has worked hard to make herself look like an independent voice, when her constituents turn on the news and see pictures of Stewart in front of a Confederate flag, it makes her job that much harder. The Cook Political Report just moved its rating of her district from “Toss-up” to “Leans Democratic,” noting not only that Democrats nominated a strong candidate to oppose Comstock but also that “Stewart’s nomination could alienate independents, depress Republican interest in the Senate race and allow Kaine to run up the score in the 10th CD, compounding Comstock’s challenge.”

If you step back to see the broad national picture, the two parties look about where they’ve been for months, with Democrats holding a lead of seven or eight points in the generic ballot. But as the last couple of weeks have shown, we can’t know what kind of new controversies will emerge in the days ahead, and how they might affect people’s eagerness to turn out. What we do know is that in our polarized age, mobilization is more important than persuasion, and the side whose voters are angrier tends to be the one that wins, especially in midterms.

And I’m pretty sure that between now and November,  Trump is going to do some more things that make Republicans uncomfortable and Democrats enraged.

Read more:

Jennifer Rubin: The political terrain turns toxic for vulnerable Republicans

Laura Bush: Separating children from their parents at the border ‘breaks my heart’

Paul Waldman: Republicans could finally be willing to stand up to Trump — to save their own skins

Jennifer Rubin: Trump’s cruel policy leaves him more isolated than ever

The Post’s View: The Trump administration created this awful border policy. It doesn’t need Congress to fix it.