On Tuesday, many Americans will focus on whether Donald Trump or Vice President Kamala Harris will be the 47th president, but there are down-ballot races that may be just as important in determining the balance of power in Washington.

Notably, the road to controlling the House of Representatives increasingly appears to run through two deep-blue states, California and New York, where a combined eight seats — four in each — are in play.

If either party wins a decisive majority of these eight, they will almost certainly have an inside track to controlling the House, and thus, determining whether Trump or Harris will be able to push through their agenda, or be stymied by an unfriendly Congress.

Surprisingly impressive GOP performances in both states in 2022 helped flip the House, but now Democrats believe they can retake these seats, and with it, the House.

In New York, Democrats are targeting four seats Republicans won two years ago, all by less than 5 points, and all districts that voted for Biden in 2020.

Closer to home, as I wrote in these pages last July, of the California House races considered toss-ups, Democrats are eying four in particular. Three are currently held by Republican incumbents, and one — California’s 47th district — has an open seat following incumbent Rep. Katie Porter’s loss in the Senate primary.

Fox Los Angeles has said the 47th could determine the balance of power in the House, and the GOP is intensely focused on what should be a winnable race here.

Two years ago, Porter narrowly beat Republican Scott Baugh, despite Porter outspending Baugh by $25 million. Now, Baugh is running again, facing Democratic state Sen. Dave Min in an increasingly combative campaign.

The race figures to be extremely close, with Baugh holding just a 3-point lead (49% to 46%) per University of Southern California polling. According to Politico, that poll also found that despite the district leaning Democratic, Min’s personal issues — he was arrested for drunk driving last year — are hurting him.

Two other Southern California districts — the 41st and 45th — are currently held by Republicans, Reps. Ken Calvert and Michelle Steel, respectively, although they are solidly toss-up races.

Indeed, Calvert and Democratic challenger Will Rollins are deadlocked at 46% each per the aforementioned USC poll, which also noted that Rollins is attracting “a small but significant number of GOP-leaning voters” per Politico.

Calvert, who is the longest-serving Republican in California’s congressional delegation, beat Rollins by 5 points in 2022, but is facing a much tougher challenge now. Despite Cook Political Report rating the district slightly Republican-leaning (R+3), Cook also considers the race a toss up.

National Democrats are upbeat about Rollins’ chances to flip what could be a critical seat, according to Elle Kurpiewski, political director for Democratic HQ of the Desert, and have poured more than $6 million into the race, up from roughly $875,000 in 2022.

The 45th District, one of just 19 nationally — including five in California — that is represented by a Republican but voted for Joe Biden in 2020, is also being targeted by both parties.

Republican incumbent Michelle Steel is slightly trailing Democrat Derek Tran 45% to 43% according to the USC poll, well within the margin of error. Steel also has a history of outperforming, winning by 5 points in 2022 despite Biden carrying the district by 6 points in 2020.

That being said, Cook rates this one a toss up and slightly Democratic-leaning (D+2), and Steel’s extreme positions on abortion and LGBTQ issues could hurt her.

It remains to be seen whether abortion will play the same role it did in 2022, although Tran has made Steel’s opposition to abortion even in the cases of rape, incest or the health of the mother a centerpiece of his campaign.

Another California district — the 27th — is worth watching.

Like the 45th, Biden won this district by 12 points in 2020, although Republican Mike Garcia won in 2022 by 6 points.

The district, also considered a toss up is ranked D+4 by Cook, and Democrat George Whitesides holds a slight 1-point lead (44% to 33%) per USC polling.

To that end, Garcia has based his campaign around kitchen-table issues such as the economy, immigration and cost of living, while Whitesides has attempted to paint Garcia as a supporter of Donald Trump and staunch opponent of abortion.

A pro-cryptocurrency Super PAC is backing Garcia, who is hoping his military background and Hispanic heritage are a boost in a heavily Hispanic district that is the home of multiple defense contractors.

While elections in presidential years tend to be different than midterms, both parties are almost certain to use similar strategies. Democrats will focus on Republican opposition to abortion and attempt to paint all Republicans as MAGA extremists loyal to Donald Trump.

Conversely, Republicans, and particularly those in California and New York, will double down on their support for lower taxes, a stronger border and policies that bring down the cost of living.

Ultimately, if Republicans can hold onto their current seats in New York and California, while adding California’s 47th, it is highly likely that the GOP controls both chambers of Congress.

For their part, if Democrats flip a majority of these seats, Congress will almost certainly remain divided, frustrating either Donald Trump or Kamala Harris.

Douglas Schoen is a longtime Democratic political consultant.