This post has been updated.

It's (special) Election Day in Georgia, when the seemingly endless race between Democrat Jon Ossoff and Republican Karen Handel finally concludes. And with it will surely come all kinds of different takes about what, precisely, the result means. This is what happens when you have only a handful of special elections in small congressional districts between the 2016 and 2018 elections.

Some special election upsets have previewed shifts in power in the next election, but we also need to remember that this is 1 out of 435 congressional districts. What happens in suburban Atlanta may or may not translate to the rest of the country.

And indeed, the district we're talking about Tuesday is highly unusual -- in a way that makes firm predictions based on Tuesday's result quite difficult.

Democrats are fond of pointing out that Georgia's 6th district went for Mitt Romney by 23 points in 2012, the 82nd most Republican district that year, and has gone for other Republicans by similarly large margins in recent years. Republicans, meanwhile, point out that it's a district President Trump won by less than two points in November.

It's exactly the kind of highly educated, suburban district that proved uniquely bad for Trump in November 2016, even as he won. And it would seem unusually ripe for an anti-Trump upset eight months later — much more so than just about any other district on the map.

The 6th district is the bluest one in Georgia on the map below (courtesy of Daily Kos Elections) — signifying one of the biggest shifts toward Democrats in the 2016 presidential election.

In fact, only five out of 435 districts trended more against Republicans in the 2016 presidential election. And four of them were in highly unusual Utah, where many Republicans -- especially Mormons -- voted for independent candidate and Utah native Evan McMullin over Trump.

Here are the top 10 anti-Trump shifts, with Georgia's 6th at No. 6:

District Member Party Clinton margin ’16 Obama margin '12 Pro-Clinton shift
UT-03 Jason Chaffetz (R) -23.9 -58.8 34.9
UT-04 Mia Love (R) -6.7 -37 30.3
UT-01 Rob Bishop (R) -27.3 -57 29.7
UT-02 Chris Stewart (R) -14 -38.8 24.8
TX-07 John Culberson (R) 1.4 -21.3 22.7
GA-06 Tom Price (R) -1.5 -23.3 21.8
TX-02 Ted Poe (R) -9.3 -27.3 18
TX-22 Pete Olson (R) -7.9 -25.4 17.5
CA-33 Ted Lieu (D) 41.3 23.8 17.5
TX-32 Pete Sessions (R) 1.9 -15.5 17.4
VA-08 Don Beyer (D) 52.6 35.4 17.2

So if it's a tight race or a modest GOP edge, would that really portend terrible things for Republicans? Or would it instead be a sign that the political map Trump redrew in 2016 might just have some staying power? It could certainly be either.

And the latter may not be such a bad thing for the GOP. Trump, after all, won 30 out of 50 states — 60 percent — and 230 out of 435 congressional districts — about 53 percent of all districts and more than Romney. Trump's ability to bring new white, working-class voters into the GOP fold actually allowed him to compete and win in more territory than Republicans are accustomed to (think Pennsylvania, Michigan and Wisconsin). If Republicans are suddenly more competitive in these areas at the expense of losing some ground in highly educated suburbs like those in Georgia's 6th, that may be an okay bargain. (Paul Kane has much more on this for those who are interested.) At the very least, it wouldn't be a shocking result.

And then there's the runoff — and specifically, the unusual setup Georgia uses, in which all candidates run in one primary, and then the top two advance to the final. The first time around, two months ago, Ossoff took 48 percent and Handel took 20 percent, but the crowded GOP field as a whole beat Democrats 51 percent to 49 percent.

History doesn't provide a ton of guidance about how that will shake out one-on-one. The only states with runoffs like this are California, Louisiana and Washington state. FiveThirtyEight ran the numbers in 181 such runoffs since 2008 to see whether Ossoff might still have a shot even if Democrats didn't win a majority of the vote Tuesday. The verdict was yes:

Out of 21 races in our database where a candidate won the plurality in the first round but her party lost the aggregate party vote, the candidate nevertheless won the runoff 11 times. For instance, Republicans combined got more of the vote in Washington’s U.S. Senate primary in 2010, but Democratic incumbent Patty Murray got the plurality of the vote. Murray went on to win the second round over Republican Dino Rossi.
Plugging Ossoff’s numbers into the formula above, we come up with a projection that he’d win the runoff by 4 percentage points.

The last time we saw a similar setup was in the California 50th district special election in 2006. And it was quite similar.

As with today in Georgia, Democrats were thirsty to prove that an unpopular Republican president — then George W. Bush — was a liability jeopardizing his party's midterm hopes by targeting a conservative-leaning district. They united around one candidate, Francine Busby, who led Republican Brian Bilbray 44 to 15 percent on primary day. But the crowded GOP field overall outpaced Busby and the Democrats 53 to 45 — quite similar to what we're seeing in Georgia's 6th. In the June runoff, Democrats narrowed the gap from 8 to 4 points, but still lost.

Another analog is Mississippi's conservative 1st district special election in 2008. There, Democrat Travis Childers led Republican Greg Davis 49-46 in the primary, with Democrats overall leading by 3 points, 51-48. And again, Democrats did better in the runoff, winning by eight.

So there is certainly precedent for a Democrats falling short of a majority but gaining ground in the special election in a tough district. Ossoff will need to gain about two points on his primary showing, while Handel basically needs to hold together all those Republican voters.

It's expected to be close, and Democrats would sure love to hail an Ossoff victory as a sign of doom ahead for the GOP. But let's always remember that this district is quite different from others in the age of Trump, and that this is a special kind of special election held 15 months before the 2018 midterms.