Today, all eyes in the political world are turning to Tennessee. There's a special election for an open House seat happening today, and it could send shockwaves through Washington no matter who wins the race. If the Democratic candidate wins, it is going to boost Democratic hopes of a "blue wave" election in next year's midterms in a big way, while simultaneously causing deep fear within the Republican Party. If the Republican wins with a small margin of victory, the same thing is going to happen (but in a more subdued way). The only way the election results aren't going to cause a shockwave is if the GOP candidate scores a sweeping victory with at least a double-digit margin.

That would be shocking in its own right, because that's not what the polls show at all. I should start with the caveat that polling House races is tricky to begin with, and polling special elections is even trickier. Predicting who will actually turn out and vote is very hard to do for special elections. Having said all of that, though, the latest poll was somewhat of a bombshell, showing the Republican ahead by only two points.

This is a district which voted for Donald Trump last year by a 22-point margin and re-elected a Republican to this House seat in the same election by over 21 points as well. It's a pretty solid-red district, in other words. But there used to be a district in Nashville that sent Democrats to Congress that was gerrymandered out of existence. The Nashville district was divided in three and the pieces were added to other (redder) districts, to deny Democrats the Nashville seat. So the big question tonight is whether Nashville voters turn out in bigger numbers than all the rural areas in the rest of the district, which could actually lead to an upset.

Right now, Democrats have much more voter enthusiasm in their base than Republicans do. People are angry at Trump and highly motivated to "send him a message" with their vote. Republicans don't have the same burning motivation, and Trump's approval ratings have taken a big downswing (which started during the government shutdown). Trump is now underwater in the polls to the tune of 12-14 percent (on average), and one recent Gallup poll showed him a whopping 24 points underwater (36 percent job approval to 60 percent disapproval). Some voters who voted for Trump so he could bring prices down "on Day One" have been sorely disappointed at his actions since he got in office (which have just made the problem worse, for the most part). Meanwhile, Democrats want to see their elected representatives fighting back, as hard as possible.

So far, in all the special House elections this year, Democrats have done what can only be called a stellar job of shifting the electorate. Back at the start of April, two red districts in Florida sent Republicans to Congress -- but the vote shift was notable. In one, the Democratic candidate outperformed Trump's 2024 result by 16 points. In the other, the Democrat did 23 points better. In special elections in September in Virginia and Arizona, the Democrat won and shifted the margins 16 and 17 points, respectively. Democrats also cleaned up in the non-House races in last month's elections, dramatically shifting voting trends in just about every race they won. That's the backdrop for tonight's results in Tennessee.

I should mention that most Democrats don't fully expect Aftyn Behn, their candidate in Tennessee, to win. That is seen as too much to hope for. A win would be wonderful, of course, but 22 points is a huge margin to overcome. But the race has been interesting because both sides have poured so much money into it. Republicans normally wouldn't even bother with a district this red, but they are clearly worried and are spending heavily on Matt Van Epps. Democrats have spent a lot on ads as well, after seeing how close the polling was getting.

The most notable thing about the race so far is that Behn has done so well. She's a solid progressive in a very red state, where most political strategists would have thought a more moderate or centrist Democratic candidate might do better:

Ms. Behn won the Democratic primary race with an unabashed record of progressive activism and policy positions that conventional political wisdom would say are far too liberal for a state that once elected more centrist Democrats.

She has been vocal in her support for transgender people, tougher gun laws and abortion rights, stances that many Republicans firmly disagree with.

This has led the Van Epps campaign to label her "the A.O.C. of Tennessee." But political labels and pigeonholing might not be the biggest factor here. Instead, it might be the message:

[Aftyn] Behn, a 36-year-old left-leaning state representative, has run as a change candidate focusing on affordability, decrying high prices, inflation and GOP economic policies such as Trump's tariffs. "If we get close," she said in an interview with The Washington Post, it will be because of the "affordability crisis that we are experiencing in Tennessee and the fact that the federal administration has not delivered an economic agenda to address the needs of working people in the state."

Economic populism is fast emerging as the central theme Democrats will be using in next year's midterms, so Behn's candidacy might be a good test of how well such messaging plays even in very red districts. Behn certainly is highlighting things that a whole lot of voters deeply care about:

"It is a matter of life and death for my neighbors who live on TennCare in the aftermath of the big, ugly bill," [Aftyn] Behn said, referring to Trump's budget passed earlier this year. She added that she would be a vote to restore the Medicaid funding that Republicans cut in that legislation. "That would save lives in my district, and I would absolutely join the coalitions of legislators who want to extend [Affordable Care Act] subsidies."

Behn is even urging the Democratic Party as a whole to adopt the message she's been using:

"After having knocked thousands of doors across the state, talking about really combative issues, it's clear that people have a plurality of opinions and thoughts," Behn said. "Especially folks that live in rural towns, they have more populist opinions. And so when you're running on rooting out corruption and making multinational corporations pay what they owe in taxes, as a working mom buying baby formula, it really resonates."

. . .

But, Behn said, she believed winning the districts like the Seventh would be possible if the party and its candidates were willing to adopt the popular "pro-worker and anti-corporate" slant of Democrats like herself.

"This is the choice in front of us: Do we want to be a party that is bankrolled by the same corporations that are selling us out?" Behn asked. "Or do we want to be a party that is leading the vanguard to protect workers and to fight for working families?"

The Democratic Party seems to be coalescing around affordability as their big issue next year. This has been the key to winning several races already, for a wide spectrum of Democratic candidates (both progressives and moderates). So it's already unifying the party's message, and the result in Tennessee tonight will likely only reinforce that.

It will be interesting to see the returns come in tonight, that's for sure. As mentioned, hoping for a win might be a sign of overconfidence for Democrats. This is a very red district, after all. But even a loss with a margin in the single digits would be a win, in a way. If a progressive Democrat can shift the voting patterns of a red House district in Tennessee by 15 or more points, that is going to reverberate across the political landscape.

One result of such an outcome might be a whole slew of GOP House members suddenly deciding it might be a good time to retire rather than run for re-election in 2026. If there truly is a blue wave on the horizon, maybe getting out before it hits is the smart thing to do?

If Democrats really are doing 15 or even 20 points better than they did in 2024, then that will make a whole lot of districts into new battlegrounds. If even Trump having won the district by 16 or 17 points is no guarantee of a Republican victory in 2026, then that will mean an enormous shift in the entire midterm landscape. More Republican money will be spent in districts previously considered "safe GOP," which means less money will be available for other battleground states and districts.

This should have been a real sleeper of an election, with the Republican easily coasting to victory. It's not. Normally, I wouldn't have even bothered watching the returns come in tonight, since the outcome should have been a foregone conclusion. But instead this could be a real bellwether election, so my eyes (as well as plenty of others) will indeed be turned to Tennessee tonight.

-- Chris Weigant

Follow Chris on Twitter: @ChrisWeigant