Absent an alien invasion, the zombie apocalypse or the sudden re-annexation of California by Mexico, Donald Trump will be the Republican candidate for president. It’s time to move on to the real question: Can he beat Hillary Clinton?

You’re darn right he can.

This runs contrary to conventional wisdom, of course. Then again, conventional wisdom also said (a) that he wouldn’t run, (b) that establishment candidates like Jeb Bush, Scott Walker and Rick Perry would crush him in the primaries, and (c) that the Republican electorate would never accept a social liberal who donates lavishly across the political spectrum and doesn’t seem terribly interested in any ideology other than “America First.”

What’s more, Trump’s foes on both sides of the aisle note that the Democrats’ current structural advantage in the Electoral College, where they walk in the door with big states like California (55 votes), New York (29) and Illinois (20) already in the bag, make it almost impossible for the GOP candidate to get to the magic number of 270.

They gleefully point to surveys showing that either Ted Cruz or John Kasich — the winner of exactly one primary — would fare better hypothetically against Clinton in the general election. Indeed, 90 percent of “top operatives” in battleground swing states recently assured Politico that Clinton will clobber Trump.

Polls, however, can change. Already, one survey has Trump within 3 points, and a recent Rasmussen poll showed Clinton and Trump tied at 38 percent apiece. Trump has already picked up 5 points on Clinton in just the past month. And while it’s true that Trump currently has high negatives among voters (62 percent), so does Hillary (56 percent).

Further, the media has consistently underestimated Trump’s genuine appeal to the white working class, which is tired of being the one group in America it’s OK to scorn.

What doesn’t take Trump down only makes him stronger and more popular. Every rival who’s rushed him headlong has been eliminated.

Does anyone think that, in the debates, Hillary will be able to withstand the blunt-force trauma the braggadocious billionaire deployed to knock Jeb and his other rivals out of the race?

Trump won’t hesitate to hammer her, and everything from Monica Lewinsky and Bubba’s “bimbo eruptions” to Whitewater and Benghazi will be on the table. He’ll also saddle her with the miserable Obama economy — seven straight years of anemic growth below 3 percent, the coal industry collapsing, a record number of able-bodied men and women out of the workforce. Millions will cheer.

In the last few primaries, Trump outperformed his poll numbers by 6 percent (New York) to 12 percent (Pennsylvania). Which indicates that — surprise — folks sometimes lie to pollsters even as they secretly admire Trump’s freewheeling positions on such hot-button issues as illegal immigration, Islamic terrorism and the Obama administration’s diplomatic ineptitude.

Finally, there’s this: What doesn’t take Trump down only makes him stronger and more popular. Every rival who’s rushed him headlong has been eliminated. Every time he says something that’s the “last straw,” his numbers jump.

In the end, of course, it will come down to turnout. Can Trump pick up enough disaffected Democrats in places like Pennsylvania and Ohio to offset the Democrats’ advantage among minorities and force them to play defense in states they normally take for granted?

Not since the bitter Adams-Jefferson election of 1800 will the nation have seen such a no-holds-barred, down-and-dirty slugfest. But after 16 years of misguided Bush interventionism and pallid Obama apathy, the momentum is on Trump’s side.