With Republican challenger Sam Brown leading Sen. Jacky Rosen (D-NV) by a few thousand votes out of the more than 1.2 million votes cast, the Nevada Senate race – crucial to the balance of power in the Senate – remains too close to decide it.

Brown, an Army veteran who lives in Reno, has a lead of 6,034 — or 0.5 percent — as of Wednesday morning. Whether he can maintain or expand that lead depends on where the remaining votes fall.

With fewer than 11,000 votes counted in Nye County — which still hasn’t processed mail-in ballots — Brown is likely to increase his lead.

The race will then be decided by the remaining absentee ballots in Clark and Washoe counties, which are expected to go in Democrats’ favor. However, the size and scope of these voices remain unknown. Mail-in ballots postmarked by Election Day will be counted as long as they arrive by Friday. In the 2022 midterms, 6 percent of all votes in Clark and 3 percent of all ballots in Washoe were received after Election Day.

Currently, Rosen is ahead of Clark by about 5.3 percentage points and Washoe by 2.4 percentage points. By comparison, in a smaller electorate, Sen. Catherine Cortez Masto (D-NV) won Clark by 7.8 percentage points and Washoe by 4.3 percentage points—and she won a nail-biter by less than 1 percent overall.

If the margin is slim, the race may be about curing the ballot signature. As of 3 p.m. on Election Day, the Secretary of State’s Office reported that 27,973 ballots require correction or voter signature verification. This happens when election officials notice a discrepancy between the signature on a ballot and the voter’s signature on other documents.

This number does not include ballots returned on Nov. 3 or later, including ballots dropped in mailboxes on Election Day.

Of these, around 40 percent were occupied by non-partisans. About 35 percent were Democrats and 26 percent were Republicans. Secretary of State Cisco Aguilar also noted that ballots that required a signature cleanup were disproportionately cast by younger voters.

If Brown wins, polls show it would be a big surprise. Rosen led the polls throughout the cycle, including by a large lead that both campaigns considered unrealistic. Even though the polls were closer in the end, analysts still expected the race to favor Democrats.

Rosen is currently more than 4 percentage points ahead of Vice President Kamala Harris — a dynamic that polls have predicted. However, given that Trump’s lead in Nevada is nearly five percentage points – a larger margin than the dead heat predicted in polls – his overperformance in the state could be enough to push Brown over the finish line.

If Rosen can hold, it will be because too many Trump voters left the rest of the ballot blank, did none of the above, voted for a third party, or split their electoral votes. For example, Rosen is leading in Washoe County, which Harris is losing. And while her raw vote count is very close to Harris’s, Brown is more than 60,000 votes behind Trump.

Currently, Republicans have flipped seats in West Virginia, Ohio and Montana. While the races have not yet been called, Democrats are positioned to hold seats in Arizona, Michigan and Wisconsin, while the Democratic incumbent is expected to lose in Pennsylvania.

The outcome of Nevada’s Senate election will determine the size of the Republican majority – crucial to confirming various Trump appointments and policies. For example, in 2017, Republicans held 52 seats but were unable to repeal the Affordable Care Act due to three Republican defections. The larger the majority, the easier it will be for Trump to achieve his desired results.

It is also very important for the 2026 midterm elections. If the Democrats lose four seats, they must gain four to regain the majority – the path to get there is difficult but possible.

But if Rosen loses and Democrats need five seats, the Senate map likely won’t provide enough options for that, making the Senate’s Republican majority more durable for the duration of Trump’s term.