Back in September, President Trump caused a stir by bringing a not-quite-accurate map into the Oval Office. The map extended the forecast for Hurricane Dorian into a small sliver of Alabama — evidently with a Sharpie. It was an apparent attempt to bolster Trump’s false claim that the state had been endangered at the time.

And now he has brought another Trumpified map to the Oval.

At a school prayer event Thursday, Trump’s desk for some reason had a giant red-and-blue map on it. The map had nothing to do with prayer, mind you, and he didn’t use it during the event. It was a map of the 2016 election, by county. Some wagered that the map was some kind of security blanket — an overwhelmingly red map reflecting Trump winning the vast majority of counties in 2016, just sitting there in case Trump needed a pick-me-up or an illustration of his success.

Except the map, perhaps not surprisingly, overstates Trump’s actual victory.

Here’s what the map looked like in some photos snapped from the event:

This time, the map doesn’t seem to have been altered by Trump or the White House. Instead, it’s a large printout of a map that has circulated on social media.

Several supporters promoted the map in 2017 as a sign of Trump’s electoral formidability. If you look closely at the photos above, you can see it’s the same map — down to the note about Alaska: “County level data not available in Alaska.”

But not only is it missing the areas of Alaska that Hillary Clinton won — most of the state should be shaded blue — it’s also got dozens of other counties that she won in Trump’s column. The number of counties won by Trump on his map: 2,680. The actual number he won: 2,626, according to the Associated Press.

You can see the incorrect 2,680 number if you look closely at one of the photos. The Clinton numbers are more difficult to make out, but the rest of the map exactly matches the one shared on social media in 2017. Trump’s map docks Clinton 33 counties. She won 487 in AP’s final count; she’s got 454 on Trump’s map.

And it also sharply understates Trump’s popular-vote loss: It has Clinton taking 62.1 million votes vs. 61 million for Trump — a 1.1 million-vote margin. The actual margin was 2.8 million votes — or Clinton 65.8 million, Trump 63 million.

There is, of course, a simple explanation for where the map came from: It was incomplete results, taken before all the votes came in — most notably before many very blue areas of California were counted.

Clinton’s popular-vote lead did indeed stand at 1.1 million at one point. It was on Nov. 15, a week after the election, according to a contemporaneous tweet from the Cook Political Report’s David Wasserman, who does yeoman’s work tallying vote totals for days and weeks after an election.

So the map was perhaps accurate at one point, but that point happens to be before a bunch of votes came in that added 1.7 million votes to his popular-vote loss and turned Trump’s map less red.

It’s not the first time Trump has used incomplete results that overstate his actual victory at the county level. Trump tweeted a different county-level map in October that also had eventual Clinton counties shaded red, as The Post’s Philip Bump wrote at the time.

But as Bump also noted, the most significant takeaway is this: Even an accurate and up-to-date map would be highly misleading, because Trump’s overwhelming victory in number of counties owes to the rural ones in which he dominated being much-less populous. He still lost the popular vote.

Apparently, though, he’d prefer it to have been by a smaller margin.

Philip Bump contributed to this report.