Democrat Jon Ossoff came tantalizingly close to winning the "jungle primary" in Georgia's 6th district on Tuesday. Because he fell two points short of an outright majority, he'll now face Republican Karen Handel in a runoff for the seat vacated by Secretary of Health and Human Services Tom Price. Democrats want to take the almost-victory (which could still turn out to be a victory) as a sign of things to come, while Republicans want to believe that everything is going to be fine for them. Given that special elections don't necessarily prove much (and a movement of a couple of points in one direction or the other certainly doesn't), what are the chances that there will be a genuine "wave" election in 2018?

This is an important question.

If the Democrats can take back either house of Congress, the political landscape in Washington would be utterly transformed. All legislation on conservative goals would immediately cease. Armed with subpoena power, Democrats would begin vigorous and vexing investigations of the Trump administration — on Russia and who knows what else. Not only that, the new Democratic chair of the tax-writing committee in whichever house they hold would immediately order the IRS to turn over Trump's tax returns (which is within the committee's power); the ensuing lawsuit would no doubt go all the way to the Supreme Court. If Democrats were to take the Senate (less likely than the House given who's up for re-election, but still possible), you can bet they'd refuse to confirm any nominee if a Supreme Court seat opened up, in retaliation for what Republicans did to Merrick Garland. Things would get even more interesting than they are now.

So the stakes are incredibly high. And wave elections aren't that unusual; in fact, in recent years they've become more rule than exception in midterm elections. A wave isn't defined by a set number of seats changing hands. Instead, it generally means that the characteristics of each district and each candidate are at least partially washed away by a broad national trend. Ordinarily safe seats become suddenly contested and strong candidates can lose, if they're in the wrong party. It's what happened in 2014 when Republicans took the Senate, in 2010 when they took the House, and in 2006 when Democrats took both. In all those cases, the opposition's voters were motivated by dislike of the sitting president to turn out in large numbers, sweeping out incumbents who might have managed to win in a different year.

While we're still more than 18 months away from the 2018 election, signs are surely pointing toward something similar happening. The Democratic base is more energized than it has been in anyone's memory, filling town hall meetings, organizing "Indivisible" groups (the organization claims that 5,800 have been created), and flooding local Democratic Party chapters with volunteers. While they may have fallen short in the special elections in Republican districts in Kansas and Georgia, what's most telling is how close they came. And as Harry Enten pointed out, "According to the weighted average of the past two presidential elections, there are 48 House districts that were won by GOP candidates in 2016 that are bluer than Georgia 6 [...] And Democrats need to win just 24 Republican-held seats for control of the House."

There are also ways in which the prediction of a wave election to come can become a self-fulfilling prophecy. If you're a Republican member of Congress from a swing district, looking at President Trump's weak approval ratings and getting yelled at by your constituents over the failed attempt to repeal the Affordable Care Act, this may start to seem like a good time to retire and cash in with a sweet lobbying gig. Chairman of the House Oversight Committee Jason Chaffetz (R-Utah) just announced that he won't be running for re-election, and you'll probably be seeing many more Republican members decide that the time has come to move on.

At the same time, the most talented potential GOP candidates may choose to hold off on their congressional ambitions. If there really is going to be a wave election, running for an open seat or challenging a Democratic incumbent would seem like a fool's errand; better to wait for a more opportune moment. On the other side, Democrats are practically lining up to run not just for Congress but for offices all the way down to dog catcher.

And if Trump remains unpopular, Republicans could face a dispirited base of their own, not to mention that many voters in the middle would choose to express their displeasure at the president the way they so often do, by voting for the other party for lower offices.

Of course, nothing is guaranteed, not by a long shot. Trump could rack up a bunch of successes and reverse his standing in the polls. Republicans' relentless efforts to keep Democrats from voting could bear fruit. The election might be canceled after we exchange nuclear attacks with North Korea. It's all possible. But if next November things look like they do today, a wave will be on its way, and the Trump presidency will be in even more trouble than it is now.