Democrat Philip Spagnuolo won a special election for the Belknap 3 House District in New Hampshire Tuesday night, adding yet another state legislative flip to Democrats’ already impressive roster of Trump-era special election wins.

He won by a 7-point margin in a district that Trump carried by 12 percentage points, making for a very impressive 19-point swing toward the Democrats. Meanwhile, over in Connecticut Democrats flipped another seat — House District 120 — winning a narrow 51-49 race in a seat that Clinton carried 49-47.

Earlier in the evening, a Democrat running for a seat in deep red Kentucky pulled off an even more impressive swing, losing by “only” 34 points in a district that Trump carried by a landslide 79-17 margin.

The New Hampshire House is enormous, so a single seat there doesn’t make a huge difference. And the 28-point improvement on Hillary Clinton’s results in Kentucky is at best a moral victory. But in the aggregate, special elections are painting a picture of a building Democratic wave. And since Trump took office, Democrats have picked up an impressive 41 seats in elections across the country.

Democrats are cleaning up in special elections

According to an extremely useful and comprehensive spreadsheet compiled by Daily Kos, across 70 special elections in 2017, Democrats ran 10 points ahead of Clinton and 7 points ahead of Obama’s 2012 results. Those numbers have accelerated into 2018. Across 16 races, Democrats are running 27 points ahead of Clinton and 15 points ahead of Barack Obama.

Historically speaking, special election results usually are somewhat predictive of midterm general election outcomes, though I don’t think anyone believes it’s realistic for Democrats to obtain a nationwide 27-point swing relative to Clinton’s numbers.

Meanwhile, the special elections are already having real-world impact.

Wisconsin Gov. Scott Walker has decided to leave a number of formerly GOP-held seats vacant rather than schedule special elections his party might lose, national Republicans are pushing the panic button on an upcoming special House election in Pennsylvania, and GOP leadership is letting scandal-plagued Rep. Blake Farenthold stick around in his seat rather than risk a special election.

What’s ahead for Democrats in November

The early showings look positive for Democrats heading into the 2018 midterms.

The entire House is up for grabs, as it is every two years. Democrats would need a wave election, winning a net of 24 seats to take the majority. The good news for Democrats is that they are far out-performing Republicans in generic ballot polling. And modeling based on historical data looks good for Democrats, too. It’s plausible for them to end Election Night having taken back the House.

The picture in the Senate looks less positive. Republicans hold 51 seats, so, in theory, Democrats only need a net gain of two seats to take back the chamber. But the group of Senate seats up in 2018 is made up overwhelmingly Democrats. The party will defend a massive 25 seats, compared with just eight for Republicans. It’ll be a battle for Democrats to take back the upper chamber.

For now, we’re months away from November. Polls changes and fundamentals change. But if special elections are any indication, we’re heading into a true contest this fall.