These six House races could decided whether Democrats or Republicans control Congress

Resources are pouring into the few truly competitive congressional races expected to help determine the balance of power in Washington next year.

Democrats need to flip just four seats to take back control of the House, while Republicans hope to expand their majority and make it easier to get priorities over the finish line, something they have struggled to do in a divided government.

While the most hotly contested House races tend to involve newer incumbents still building their name recognition, a few long-time veterans of Congress are facing competitive contests as well due to demographic shifts in their districts.

Overall, House control is likely to come down to the 16 Republican-controlled districts that Democratic President Joe Biden carried in 2020 and the five Democratic-controlled districts that Republican Donald Trump won. Such districts are rich targets for both parties.

Here's a look at six of these toss-up races to watch this fall.

Maine's 2nd Congressional District

National Republicans have tried before to unseat three-term Democratic incumbent Jared Golden. This time, they believe they've found the right candidate in Republican Austin Theriault, a state lawmaker and former NASCAR driver.

Nearly $16 million in political ads have been reserved for the district, which Trump won twice. That's a lot of ad buys in a relatively inexpensive market. The planned spending is about evenly divided between Republican and Democratic groups, according to AdImpact, which tracks media buys. House Speaker Mike Johnson, R-La., visited the district this month, highlighting the race's importance.

Golden, a Marine Corps veteran, has bucked Biden's administration on some votes. Most notably, he was the only Democrat to vote against Biden's COVID-relief bill in March 2021.

Golden subsequently voted for major bills to increase infrastructure spending and expand benefits for veterans exposed to burn pits and other toxic environments, and he voted for Biden's centerpiece health and climate bill, referred to as the Inflation Reduction Act.

New York's 4th Congressional District

Democrats see Long Island as a prime opportunity to recapture congressional seats and reclaim a House majority, starting with a race featuring a rematch of two years ago, freshman Republican Rep. Anthony D'Esposito versus Democratic challenger Laura Gillen.

Groups plan to spend nearly $11 million on advertising in this race with Democratic-aligned groups reserving nearly $7 million in ads and Republicans reserving nearly $4 million, according to AdImpact.

Gillen also had an advantage in cash on hand as of June 30, according to the Federal Election Commission, with $2.5 million versus nearly $2.2 million for D'Esposito. It's unusual for the challenger to have more cash on hand than the incumbent.

D'Esposito is a former New York City Police detective who won in 2022 even though Biden carried his district by about 15 percentage points in 2020. D’Esposito has made public safety a priority of his campaigns and boasts of delivering millions of federal dollars to help local law enforcement.

Gillen is a former supervisor of the town of Hempstead, the largest town in Nassau County, and has emphasized support for a woman's right to choose an abortion.

Pennsylvania's 8th Congressional District

Matt Cartwright is used to competing in close races — and winning. The Democrat began his career in Congress in 2013. Judging by the resources pouring into this race, he's in another dogfight. Democratic groups plan to spend about $13 million on ads and Republicans plan to spend more than $10 million, according to AdImpact.

His opponent is Republican Rob Bresnahan, who is emphasizing his experience as the CEO of an electrical contracting company and reinvesting in local communities.

Cartwright represents a northeast Pennsylvania district that sided with Trump in 2020 even though Biden is a Scranton native.

Cartwright voted against a sweeping House GOP bill to build more border wall and impose new restrictions on asylum seekers, but he is emphasizing in ads a vote to deport immigrants who commit crimes as he tries to blunt Republican criticism on border issues.

Arizona's 1st Congressional District

Republican Rep. David Schweikert is used to winning election to Congress comfortably. Not anymore. Schweikert won his suburban Phoenix district by just 3,200 votes in 2022 against a relatively unknown rival who got minimal support from national Democrats.

This time, the House Majority PAC, which focuses on electing Democrats, is planning to spend more than $6 million on ads compared to about $4.9 million from the lead Republican group, the Congressional Leadership Fund.

Schweikert, serving his seventh term, will face Amish Shah, a physician and former Arizona state representative who emerged recently from a crowded Democratic primary as the winner.

California's 13th Congressional District

Freshman Republican Rep. John Duarte won by just 564 votes in 2022 and did so in a district that Biden carried by double digits two years earlier. That makes this Central Valley-based district an automatic priority for both parties in what will be a rematch from two years ago.

The Democratic challenger is Adam Gray, who served for 10 years in the California State Assembly.

Democratic-aligned groups plan to spend about $7.6 million on ad buys. Republicans have reserved about $6.1 million in air time, according to AdImpact.

The state's farm belt is more conservative than most of California with the cost of living and access to water for irrigation both being top challenges and priorities.

Duarte emphasizes his farming roots, growing grapes, almonds and pistachios, and says curbing Washington spending would lessen inflation. Gray touts money he's helped deliver to the region from Sacramento for water storage and to repair aging canals.

Democrats hope Gray benefits from a presidential election that drives more voter turnout as opposed to the mid-term election that often benefits the party not in control of the White House. But Duarte can take comfort from winning the March primary earlier this year with nearly 55% of the vote compared to 45% for Gray. In California, the top two vote-getters regardless of party advance to the general election.

Washington's 3rd Congressional District

Democratic Rep. Marie Gluesenkamp Perez will face Trump-endorsed Joe Kent in a rematch from two years ago that the Democrat won by less than 1 percentage point.

Republicans see Gluesenkamp Perez as vulnerable in a district that Trump won by more than 4 percentage points in 2020. Republican groups have reserved nearly $6 million in political ad buys while Democratic groups plan to spend about $5.3 million.

Gluesenkamp Perez supports abortion access and policies to counter climate change, but also speaks openly about being a gun owner. Meanwhile, Kent says Gluesenkamp Perez only pretends to be a moderate.

The southern border could be a defining issue in the race. American Action Network, a Republican-aligned issue advocacy group, has run ads showing the incumbent saying in March 2023 that “nobody stays awake at night worrying about the Southern border.” She went on to make the point that people stay awake worried about pocketbook issues like the prospect of losing their house or having a child drop out of school.

But the comment has clearly become a focal point for Republicans who blame Democrats for not doing enough to stem illegal immigration.

Gluesenkamp Perez is emphasizing in campaign ads her willingness to work with Republicans on border issues. An ad that features some local public safety officials endorsing her ends with her saying she approved the message "to do whatever it takes to secure the border and keep Washington safe.”