The 2025 election results are in, with Democrats securing key victories in several high-profile races across the country — from New York to Virginia and New Jersey, offering a potential boost of momentum heading into the 2026 midterms, Northeastern University political scientists say. 

Other analysts caution, however, that while the victories — including Zohran Mamdani’s grassroots win in New York — signal energy within the party, the results may reflect local dynamics more than a clear national trend.

In perhaps the most-watched race, Mamdani clinched the mayoral race over former Gov. Andrew M. Cuomo and Republican Curtis Sliwa. In New York, voter turnout for the mayoral race was the largest in decades. 

Another closely watched race was New Jersey’s gubernatorial contest, which saw former Navy helicopter pilot U.S. Rep. Mikie Sherrill overcome Republican Jack Ciattarelli. 

And Virginia, Democrat Abigail Spanberger secured the governor’s seat over Republican Winsome Earle-Sears, extending her party’s recent streak of statewide victories.

As of 10 p.m. EST, the outcome of California’s redistricting ballot measure, Proposition 50, remained undetermined. The measure proposed the adoption of a new congressional map that makes five districts more favorable to Democrats, potentially positioning the party to gain seats in the midterms.

David Lazer, university distinguished professor of political science and computer sciences at Northeastern, says that elections in the U.S. tend to be “thermostatic,”  meaning that they usually swing against the party that controls the White House. 

“This is certainly true of midterms, and, it seems to be true with these weird, one-year after-the-general elections,” Lazer says. “That said, there is a lot of time before the midterms, and all of the redistricting will affect the scale of the swing in the House.”

What does Mamdani’s victory signal?

Mamdani, a fresh face in New York politics, built his campaign around a deeply grassroots platform that energized younger progressives, with an emphasis on housing affordability, climate action and economic justice — all done under the banner of democratic socialism. 

Experts say Mamdani’s rise suggests a growing appetite among voters for new voices and bold ideas within the party’s ranks at a moment when the Democrats are searching for ways to contest a Republican unified government — and infuse the party with fresh personalities to propel it back into power. 

Cuomo had been seeking a political comeback after resigning in disgrace in 2021, while New York City Mayor Eric Adams ran as a centrist focused on public safety before dropping out of the race. Rounding out the field was Sliwa, a conservative radio host and founder of the Guardian Angels.

But Nick Beauchamp, an associate professor of political science at Northeastern University, says victory would test just how far the Democratic Party’s progressive energy can travel beyond New York, noting that it’s “hard to draw any firm generalizations” in New York “given the peculiarities of Cuomo, Adams, Sliwa and the ranked-choice primary.”

“A better test would be if we saw a left-leaning candidate running in a more centrist district, but we don’t really have that,” he says. 

The impact of Virginia and New Jersey

Spanberger and Sherrill’s victories are a better measure of what the national trends look like at present. 

Both “competent” center-left Democrats, Beauchamp says that “neither has notable charisma or a distinctive message, and therefore their results are likely to reflect the national mood rather than something more particular to the candidate.”

Costas Panagopoulos, distinguished professor of political science, says the clean sweep of the top races “sends a strong message to Trump” and will generate momentum heading into the midterms. 

“Democrats have been down in the dumps since bigger-than-expected losses in 2024, and tonight’s wins will fire them up and remind them the party can still win,” Panagopolous says. “This sort of enthusiasm will be crucial as the midterm cycle heats up.”

Historic turnout in New York

Panagopoulos says Mamdani’s candidacy “clearly energized” New Yorkers who may not have voted much in off-year elections, “particularly young voters and minorities.”

“While historic, the message his victory may be sending is less pro-Mamdani and more anti-establishment,” he says.

Proposition 50

Beauchamp says that, should Prop 50 pass, it “will certainly accelerate the race towards fully partisan districting.” 

“That said, the net effect on House margins is likely to be small – likely below 10 seats net when all the redistricting is done,” he says. “This is obviously a bad outcome for representative democracy, especially at the local level, so like all such worsening ratchets, perhaps the only optimism we can find is that this may finally accelerate a national movement — or court directive — towards nonpartisan districting.”

Tuesday’s election took place against the backdrop of an ongoing government shutdown, which entered its 35th day on Tuesday, making it the second-longest funding lapse in U.S. history.

Tanner Stening is an assistant news editor at Northeastern Global News. Email him at t.stening@northeastern.edu. Follow him on X/Twitter @tstening90.