Senate Control Hinges on Tight Races as Primaries Wind Down

With just four primary elections remaining before the November general election, the battle for control of the United States Senate remains as fluid as it has been all year. Democrats need a net gain of four seats to flip the chamber — a tall but increasingly plausible order given President Donald Trump’s low approval rating, the ongoing war with Iran, and the historical tendency for midterm electorates to punish the president’s party.

Currently, Republicans hold a 53-47 majority, including two independents who caucus with Democrats. Of the 35 Senate seats up for election this year (including special elections), 23 are held by Republicans and 13 by Democrats or independents. As NPR reports, the party is bracing for Democrats to pick up between one and three seats based on the current political environment.

The landscape at a glance

Trump’s approval rating hovers around 39%, with 58% of voters disapproving, compounding headwinds that historically cost the White House party seats in midterm cycles. Economic frustration over cost-of-living concerns, combined with tariffs that continue to batter agricultural states and the fallout from the war with Iran, have created a volatile backdrop for Republicans defending a map that is asymmetrical in their favor but includes several genuinely competitive races.

The remaining primaries — Michigan on Aug. 4, Minnesota on Aug. 11, Alaska on Aug. 18, and New Hampshire on Sept. 8 — will finalize matchups that could reshape the electoral landscape.

Tier 1: North Carolina — Democrats’ best pickup opportunity

North Carolina stands as Democrats’ single best chance to flip a Republican-held seat. Incumbent Sen. Thom Tillis is retiring, setting up an open contest between former Gov. Roy Cooper, a Democrat who won statewide twice even as Trump carried the state, and Michael Whatley, the former Republican National Committee chairman and a close Trump ally.

Cooper brings widespread name recognition and has consistently led Whatley in both polling and fundraising. As CNBC notes, Cooper’s ability to reduce Democratic losses in rural areas — a key skill in a state with the nation’s second-largest rural population — could be decisive. Still, Democrats have not won a Senate race in North Carolina since 2008, and Republicans remain confident that Whatley’s fundraising operation and the state’s Republican-leaning voter registration numbers will hold the line.

Tier 2: The toss-ups

Alaska

A quirk of Alaska’s election system has turned this race into one of the year’s most unusual. The entry of Dan J. Sullivan, a retired teacher who shares a name with Republican incumbent Sen. Dan S. Sullivan, has created potential voter confusion under the state’s ranked-choice voting system. Both Sullivans could appear on the November ballot. Former Rep. Mary Peltola, the first Alaska Native to serve in Congress, is running for Democrats and has led in some polls. The primary is Aug. 18.

Maine

Sen. Susan Collins faces a new Democratic challenger after the party’s original candidate, Graham Platner, suspended his campaign following a rape allegation he denies. Troy Jackson, the former state Senate president and a fifth-generation logger, was nominated on July 25 and is running on an economic populist platform. Collins has a history of overperforming in a state that Trump lost in 2024, but as NPR notes, “a path to the Senate without Maine is a very narrow one for Democrats.”

Michigan

Retiring Sen. Gary Peters leaves an open seat that has sparked a fierce Democratic primary between centrist Rep. Haley Stevens and progressive Abdul El-Sayed, a former Detroit health official. Stevens has outspent El-Sayed on the airwaves by at least eight times, according to AdImpact, and has the backing of Gov. Gretchen Whitmer and Senate Minority Leader Chuck Schumer. The winner will face expected Republican nominee Mike Rogers, who narrowly lost the 2024 Senate race in the state. Primary: Aug. 4.

Ohio

Democrats landed their preferred candidate in former Sen. Sherrod Brown, who returns for a rematch against incumbent Republican Sen. Jon Husted. Husted was appointed to the seat vacated by Vice President Vance and is now seeking a full term. Brown is focusing on kitchen-table economic issues. While Ohio has voted for Trump in three consecutive elections, Brown’s narrow 2024 loss suggests the state remains competitive under the right conditions.

Tier 3: A progressive opportunity in Minnesota

Democrats are not expected to lose the open Minnesota seat, but the primary has become a high-profile example of the party’s internal ideological struggle. Progressive Lt. Gov. Peggy Flanagan faces centrist Rep. Angie Craig in the Aug. 11 primary. Flanagan has won the DFL Party endorsement and leads in polls, while Craig has outraised her. The Republican nominee is expected to be former NFL sportscaster Michele Tafoya. No Republican has won statewide in Minnesota since 2006.

Tier 4: Georgia, New Hampshire, and Iowa

Incumbent Sen. Jon Ossoff is the only Democratic senator defending a seat in a state Trump carried in 2024, making Georgia a critical but currently lean-Democratic race. His Republican opponent is Rep. Mike Collins, who received a last-minute Trump endorsement before his runoff.

In New Hampshire, Sen. Jeanne Shaheen’s retirement has opened a seat Democrats have held for nearly two decades. Rep. Chris Pappas will face former Sen. John Sununu in a state where 60% of residents disapprove of Trump, according to a University of New Hampshire survey.

Iowa’s open seat, vacated by retiring Sen. Joni Ernst, has become more competitive than expected due to tariffs battering the state’s soybean farmers and the economic fallout of the Iran war. Democrat Josh Turek, a Paralympic gold medalist, faces Republican Rep. Ashley Hinson.

Tier 5: Texas — the long shot

Attorney General Ken Paxton’s defeat of Sen. John Cornyn in the primary — the most expensive Senate primary in U.S. history, with over $100 million in combined spending — has created an unexpected opening for Democratic state Rep. James Talarico. No Democrat has won statewide in Texas since the 1990s, but Talarico’s anti-corruption and affordability message has drawn national attention and strong fundraising.

Analysis: The path to 50

For Democrats to flip the Senate, they would need to run the table on the most competitive races. The most plausible path includes wins in North Carolina, Ohio, and either Maine or New Hampshire, with a fourth pickup coming from Alaska, Michigan, or Iowa. A wave Democratic performance could see the party net five or more seats, producing a 52-48 majority.

However, the national environment could shift. The outcome of the war with Iran, economic data between now and November, and the results of the remaining primaries will all play a role in determining whether the map continues to expand in Democrats’ favor or contracts back toward a more Republican-friendly status quo.

What to watch next

Four primary dates will shape the final battleground: Michigan on Aug. 4, Minnesota on Aug. 11, Alaska on Aug. 18, and New Hampshire on Sept. 8. Each will determine not only who appears on the November ballot but also which states emerge as true toss-ups and which solidify in favor of one party. With the Senate majority and control of the federal agenda at stake, every race counts.