Blue tsunami, wave or trickle? Races to watch as Democrats seek to flip the House

(CN) — As the nation gears up to choose its next Congress, Democrats are angling for a “blue wave” to balance the Republican Party’s grip on the presidency, Senate and House of Representatives.Early polling suggests many of the most hotly contested House races could tip in Democrats’ favor — but the degree to which that happens will have big implications for the power balance across the federal government.“It’s a blue tsunami, it’s a blue wave, or maybe a blue trickle,” said Shawn Donahue, clinical assistant professor of political science at the University at Buffalo.President Donald Trump has sought to tap into his base to increase turnout, asking his supporters repeatedly to “pretend that I’m on the ballot.”And with Trump’s approval rating in some polls hitting record lows, Democrats have taken the same approach, banking on Trump-aligned candidates to fall as voters tire of sky-high gas and grocery bills while bankrolling the Iran war.“They seem to be very comfortable with running against Trump,” Donahue said of the Democratic Party, noting the president is “deeply unpopular” with independent voters and his support among Democrats is nonexistent.“But if he still has his base, you know, he’s the best person maybe to help get those people to turn out,” Donahue said.Since all 435 House seats are technically up for grabs, Donahue is studying where parties — which he said have access to the best polling — are deciding to pull the plug and focus on more winnable districts.Here are five key races to watch in November.CA-22 Republican incumbent U.S. Representative David Valadao is facing Randy Villegas, a progressive Democrat who supports single-payer healthcare and is backed by Vermont Senator Bernie Sanders.Valadao, a former dairy farmer, is serving his sixth term. He was one of two House Republicans who supported impeaching Trump and remained in Congress after the 2022 election, along with Washington’s Dan Newhouse. He won his seat by seven points in 2024, but he is running in a new district after California redrew its Congressional maps last year.“This was a district that was gerrymandered by Democrats to become more competitive,” Donahue said. In the last election, the heavily Latino, low-turnout district swung red, but polls have suggested Latino voters are shifting toward Democrats.“If that is the case, this is a district that Valadao would have some trouble in,” Donahue said.In recent polling, Villegas appears to have a slim lead.NJ-7 In New Jersey’s 7th District, Republican incumbent U.S. Representative Tom Kean Jr. may have a bigger hurdle to overcome than Democratic challenger Rebecca Bennett: his own lengthy absence from Congress during his second term.From early March through June, the congressman disappeared, later explaining the absence as a medical emergency and saying he was diagnosed with depression. During that time, however, Kean continued trading stocks and raked in as much as $340,000, Gothamist reported.Bennett is a former Navy helicopter pilot making her first run for office.While Kean is endorsed by Trump, he’s portrayed himself as a more moderate Republican. He said in a Sept. 27 debate he opposes a planned ICE facility in Roxbury, New Jersey, and supports the Gateway Tunnel, a rail project between New York and New Jersey Trump has tried to kill.“In a strong Democratic year, this feels like a seat that’s going to be one of the first to kind of fall, and I think that the whole thing with him disappearing for a while makes Kean a lot less strong an incumbent,” Donahue said.AZ-1 Democrat Dr. Amish Shah will face Republican Jay Feely in Arizona’s 1st District. The incumbent, U.S. Representative David Schweikert, lost in the Republican gubernatorial primary to U.S. Representative Andy Biggs.Shah is a former state legislator and emergency room doctor who also worked in the NFL as a sideline physician for the New York Jets, where Feely was a kicker. Trump endorsed Feely in the primary.It’s a “swingy seat,” Donahue said. “I’ll put it like this: The district voted for Biden by about a point and a half, and then Trump by about three points.”Recent polls show Shah and Feely essentially tied.CO-8 In Colorado’s 8th District, Republican incumbent Gabe Evans is running against Democrat Manny Rutinel, a former state representative and economist in the U.S. Army Corps of Engineers. Evans is a former police lieutenant and captain in the U.S. Army.Like California’s “swingy” 22nd District, Donahue said, the Latino voting bloc here could play a major role. Unlike California’s Villegas, however, Rutinel is a more moderate candidate.In 2021, the district was “drawn to be very very competitive,” and has gone for both President Joe Biden and Trump.And this year, the controversial Republican nominee for governor, Christian ministry leader Victor Marx — who claims he cast a demon out of a teenager, befriended the late Charlie Kirk and earned a black belt in Keichu-Do, a “Cajun Christian” martial art developed by his father — presents another challenge for the GOP.“Colorado is also a state that Republicans are going to have a lot of seats that might be in play, because they have somebody that’s nuts running for governor,” Donahue said. “This guy is out there. So you know, how much does that depress Republican turnout across the state?”OH-9Voters in Ohio’s 9th District are experiencing déjà vu in the race between Democratic incumbent U.S. Representative Marcy Kaptur and Republican challenger Derek Merrin.In 2024, Kaptur beat Merrin by just over 2,000 votes, setting up a closely watched rematch in the swing state.While the candidates may be familiar, the district is new: In October 2025, Ohio redrew its congressional map, meaning the new 9th District map will be used for the first time.The shifting nature of the district could present a challenge for Kaptur, the longest-serving female representative in U.S. history. However, she managed to win in 2024 despite headwinds from Trump, Donahue said. This year, strong showings from Democratic candidates for governor and Senate could give her a boost.“Even if it’s a fairly Democratic environment, it’s still a tough district,” Donahue said.Recent polls have the candidates in another head-to-head race.One thing is clear to Donahue coming up on the midterms: “This is not going to be a good Republican year. I mean, it’s mainly a question of how bad of a Republican year is it going to be.”Subscribe to our free newslettersOur weekly newsletter Closing Arguments offers the latest about ongoing trials, major litigation and rulings in courthouses around the U.S. and the world, while the monthly Under the Lights dishes the legal dirt from Hollywood, sports, Big Tech and the arts.Additional Reads