The fix is in: Online news aggregators shut out publications that back Republicans in presidential elections.

That distressing finding from the conservative Media Research Center’s latest study is fresh proof of deep bias in these vital news sources, and so strong grounds for Congress and the Federal Trade Commission to turn up the heat — and push Big Tech to mend its ways.

MRC looked at news outlets that are most prominently featured on Apple News and Google News, and found (surprise!) none backed a Republican for president, not even once, in any election cycle dating back to 1988.

That’s right: Over the course of the 10 elections, the publications promoted most by these news feeds endorsed Democrats for the White House a full 31 times — and Republicans exactly . . . zero.

Another aggregator, Microsoft’s MSN, was only slightly less skewed: Its top five news organizations went 25-2 in backing Dems over GOPers.

The drastic skew in endorsements speaks to a much farther-ranging bias in the sources for feeds that tens of millions of Americans rely on for their daily news.

This isn’t simply about whatever edge endorsements might give Dems in elections, but about shaping how the public sees issues, indeed perceives the country and the world, long before even thinking about politics per se.

And the latest finding in no outlier: Other studies, by MRC as well as the fully nonpartisan bias ranker AllSides, show a longstanding, overwhelming general tilt to the left by online aggregators.

In April, AllSides reported just 1% of Google News articles (not counting those that are user-tailored) come from outlets ranked as right-leaning. Only 2% of Apple News’ offerings were from publications that lean right.

Even back in 2023, AllSides ranked Apple as leaning left.

“Right-leaning media is really underrepresented,” lamented AllSides’ Julie Mastrine at the time — an epic understatement.

And you can be sure the skew steers public opinion.

“Almost half of voting-age Americans own an Apple iPhone,” notes MRC’s Dan Schneider, and “all its phones come pre-installed with Apple News. Swipe right and you’re inundated with Apple’s cherry-picked news stories.”

And “most people don’t even know they are being fed a steady stream of leftist narratives.”

The damage from left-wing outlets has been enormous: Recall how they dismissed The Post’s 100% accurate scoop on Hunter Biden’s laptop just before the 2020 presidential election.

And promoted the 100% fake Russian Collusion hoax.

And denounced any discussion of a possible Wuhan lab-leak as racist conspiracy-theorizing.

In February, FTC boss Andrew Ferguson urged Apple to undertake “a comprehensive review” of its terms of service” to “ensure that Apple News’ curation of articles is consistent with those terms and representations made to consumers” — and, if not, “to take corrective action swiftly.

With control of Congress on the line as the midterms approach, we’re eager to see some hard evidence that Apple, Google and other aggregators have moved to get their content in balance.

If not, Washington may have no choice but to step in.