Introduction

Ninety-nine days remain before the November 3 general election, and the ballot voters will see in most of the country is not finished being written.

The 2026 primary season opened March 3 in Texas and North Carolina and does not close until September 15 in Delaware. Between now and then, voters in roughly a dozen and a half states and territories will still select nominees for the U.S. Senate, the U.S. House, and dozens of statewide offices.

That timing matters more than usual this cycle. Republicans hold a 53-45 Senate majority and a narrow House margin. Several of the contests that will determine control of both chambers do not yet have two named candidates.

In simple terms: the general election campaign has not fully begun in a number of the states most likely to decide who runs Congress in 2027.

Background

Thirty-three of the 100 Senate seats are on the ballot this year, plus two special elections — 35 contests in all. Democrats hold 13 of those seats and Republicans hold 22.

Ten of the seats are open, meaning no incumbent is seeking re-election. Four Democrats and six Republicans are retiring, the largest such class since 2012. Open seats reliably produce the most crowded and most expensive primaries, because there is no incumbent to clear the field.

August is the busiest month on the remaining calendar. Sixteen states and territories vote, including Michigan, Minnesota and Alaska — three of the states national strategists in both parties have flagged as pivotal to Senate control.

How the Remaining Calendar Works

The primaries still ahead fall on the following dates, per the Federal Voting Assistance Program and 270toWin:

Date	States voting
Aug. 4	Kansas, Michigan, Missouri, Washington
Aug. 6	Tennessee
Aug. 8	Hawaii
Aug. 11	Connecticut, Minnesota, Vermont, Wisconsin (plus Alabama congressional runoffs)
Aug. 18	Alaska, Florida, Wyoming
Sept. 1	Massachusetts
Sept. 8	New Hampshire
Sept. 9	Rhode Island
Sept. 15	Delaware

Two mechanics complicate the picture.

First, several states require a runoff when no candidate clears a vote threshold — a majority in Alabama, Arkansas, Georgia, Mississippi, Oklahoma, South Carolina and Texas, and lower thresholds in North Carolina and South Dakota. Louisiana applies a majority requirement to congressional primaries for the first time this year, having moved to closed party primaries for Congress in 2026.

Second, three states do not hold conventional party primaries at all. California and Washington advance the top two finishers from a single all-party ballot. Alaska advances the top four, and then decides the general election by ranked-choice voting.

The practical effect is that “the primaries are over” is not a single date. In a handful of states, the November ballot is not fully locked until late September.

The Senate Primaries Still to Come

Michigan — August 4

Democratic Sen. Gary Peters is not seeking a third term, leaving one of the cycle’s most competitive open seats.

The Democratic primary began as a three-way contest between U.S. Rep. Haley Stevens, state Sen. Mallory McMorrow and former Wayne County health director Abdul El-Sayed. McMorrow suspended her campaign on July 5, citing an inability to break through. Because ballots were already printed, her name still appears on the August 4 ballot, but votes cast for her do not count toward the nomination.

That leaves Stevens and El-Sayed. Former U.S. Rep. Mike Rogers, who chaired the House Intelligence Committee and lost a 2024 Senate bid to Elissa Slotkin, is unopposed on the Republican side.

Outside money has made this the most expensive remaining primary in the country. Combined outside spending exceeded $65 million as of mid-July — roughly three times what the two Democratic campaigns had raised themselves. AIPAC’s United Democracy Project accounted for nearly $15 million of it, split between roughly $9.3 million supporting Stevens and $5.7 million opposing El-Sayed.

Why it matters: Michigan is a genuine toss-up in November, and the Democratic primary is a direct test of whether outside spending can determine which faction of the party carries a battleground seat.

Minnesota — August 11

Democratic Sen. Tina Smith is retiring. It is the first open Senate race in Minnesota since 2006.

Lt. Gov. Peggy Flanagan carries both Smith’s endorsement and the DFL convention endorsement. U.S. Rep. Angie Craig, who represents the state’s competitive 2nd District, has stayed in the race regardless. On the Republican side, former Navy SEAL Adam Schwarze won the convention endorsement over former sports broadcaster Michele Tafoya and 2024 nominee Royce White.

Forecasters rated the general election Likely Democratic as of June. The last Republican elected to the Senate from Minnesota was Norm Coleman in 2002.

Why it matters: Craig’s decision to leave the House to run creates a second competitive race in her own district. The primary also determines whether Democrats field a statewide officeholder or a swing-district member in a state Republicans have repeatedly tried and failed to put in play.

Alaska — August 18

Republican Sen. Dan Sullivan is seeking a third term against former U.S. Rep. Mary Peltola, who entered the race in January and is the only Democrat to win a statewide election in Alaska since 2008.

Sixteen candidates filed. All appear on one ballot; the top four advance to a ranked-choice general election. Peltola had raised roughly $8.7 million to Sullivan’s $6.5 million. Sen. Lisa Murkowski, who previously backed Peltola for the House, has endorsed Sullivan.

The race has also produced litigation. A second candidate named Dan J. Sullivan was removed from the ballot and then reinstated after a judge found the Division of Elections’ removal unlawful; the Alaska Supreme Court ruled him eligible on June 29. Accusations that the similarly named candidate was recruited to confuse voters are under investigation, according to sources cited by NBC News.

Why it matters: Alaska is on the Democratic target list despite President Trump carrying the state by 13 points in 2024. The top-four format means the August result is less about elimination than about ballot position and how the four-way field shapes ranked-choice math in November.

Tennessee — August 6

Sen. Bill Hagerty faces no Republican primary opponent. Five Democrats are competing for a nomination in a state where no Democrat has won statewide office since 2006.

The more consequential Tennessee primary is for governor, where term-limited Gov. Bill Lee’s seat has drawn Sen. Marsha Blackburn, U.S. Rep. John Rose and state Rep. Monty Fritts to the Republican ballot.

Why it matters: Blackburn’s gubernatorial bid and Rose’s departure from the 6th District reshuffle the state’s congressional delegation regardless of the November result.

Massachusetts — September 1

Sen. Ed Markey, who will be 80 on Election Day, faces U.S. Rep. Seth Moulton, 47, in a Democratic primary Moulton has framed almost entirely around generational change and length of service. Moulton has also endorsed a constitutional amendment imposing congressional age limits.

An Emerson College poll in May showed Markey ahead 37 percent to 32 percent, with 29 percent undecided — Markey up 13 points among registered Democrats, Moulton ahead by six among unenrolled voters, who may participate under the state’s semi-closed rules.

Republican John Deaton, the 2024 nominee against Sen. Elizabeth Warren, is the presumptive GOP nominee.

Why it matters: The seat is not competitive in November. The primary is, and it is the clearest test this cycle of whether age and tenure move Democratic primary voters — a question with implications well beyond Massachusetts.

New Hampshire — September 8

Sen. Jeanne Shaheen’s retirement created the state’s first open Senate race since 2010 and the first for this seat since 1990.

U.S. Rep. Chris Pappas is the Democratic front-runner against Karishma Manzur. The Republican field includes former Sen. John E. Sununu, former Massachusetts Sen. Scott Brown, and two lesser-known candidates.

Why it matters: This is the last competitive Senate primary of the cycle, held eight weeks before Election Day. The eventual nominees will have less general-election runway than in any other battleground.

The House Primaries to Watch

The Cook Political Report rates 18 districts as toss-ups — the seats most likely to determine House control. As of early June, seven of them had not yet held primaries, in states voting from August through mid-September.

New Hampshire’s 1st District (Sept. 8). Open because Pappas is running for Senate. A large Democratic field is led by Stefany Shaheen, daughter of the retiring senator. In the 2nd District, Democrat Maggie Goodlander faces a likely rematch with Republican Lily Tang Williams. Both of New Hampshire’s marquee federal contests are open or contested simultaneously — an unusual alignment for a two-district state.

Minnesota’s 2nd District (Aug. 11). Craig is the only Minnesota incumbent not seeking re-election, leaving a competitive suburban seat open in a state where the delegation is split 4-4.

Michigan’s 11th District (Aug. 4). Open as Stevens runs for Senate, one of several Michigan seats reshuffled by the Senate contest.

Tennessee’s 5th District (Aug. 6). Republican Rep. Andy Ogles faces a primary challenge from former state Agriculture Commissioner Charlie Hatcher. The Democratic National Committee has identified the seat as a flip opportunity; Columbia Mayor Chaz Molder and Metro Nashville Councilmember Mike Cortese lead a five-candidate Democratic field. The 6th District is open with Rose running for governor.

Wisconsin (Aug. 11). Republicans hold six of eight seats. Democrats are targeting two, including the western Wisconsin district held by four-term Rep. Derrick Van Orden. The primaries feature a number of first-time candidates and are being read as a measure of which wing of each party currently has momentum.

Alaska’s at-large seat (Aug. 18). Runs on the same top-four ballot as the Senate race, with the added complication that at least one Democratic figure has thrown support behind an independent candidate.

Impact

The compressed back end of the calendar has three practical consequences.

Late nominees have short campaigns. A nominee chosen September 15 in Delaware or September 8 in New Hampshire has roughly seven to eight weeks to consolidate party support, retire primary debt and reintroduce themselves to a general electorate. In states with early and mail voting, some ballots are cast almost immediately.

Primary spending depletes general-election resources. Michigan is the clearest illustration: more than $65 million in outside money spent before a single general-election vote is cast.

Forecasting stays unsettled. Race ratings in states with unresolved primaries carry more uncertainty than ratings elsewhere, because the identity of one or both nominees is unknown. Alaska’s shift from Safe Republican after Peltola’s entry demonstrates how much a single candidate decision can move a race.

Analysis

Three patterns run through the remaining contests.

The first is the volume of open seats. Ten Senate retirements is the most since 2012, and open seats are where party direction actually gets contested. Michigan, Minnesota and New Hampshire are all open, all in the final stretch of the calendar, and all feature primaries that function as arguments about what kind of candidate the party should nominate.

The second is the role of outside money in low-turnout August elections. August primaries typically draw a fraction of general-election turnout, which makes each dollar of persuasion spending unusually efficient. Michigan’s Democratic primary is the test case.

The third is structural variation. Alaska’s top-four ballot, Washington’s top-two system, Louisiana’s new closed congressional primaries and Maine’s ranked-choice tabulation mean four different states are running four materially different processes to produce a November ballot. Comparisons of “primary results” across states are less like-for-like than the phrase suggests.

Conclusion

With 97 days remaining, the 2026 election is in an unusual position: the campaign that will decide control of Congress is fully underway in some states and has not started in others.

The next six weeks resolve most of it. By September 15, every nominee will be set, every runoff settled, and the November contest will finally have two names in every race.

Key Takeaways

97 days remain until the November 3, 2026 general election.
Primaries are not complete. The season runs March 3 through September 15, with roughly 18 states and territories still to vote.
Six Senate primaries of national consequence remain: Michigan (Aug. 4), Tennessee (Aug. 6), Minnesota (Aug. 11), Alaska (Aug. 18), Massachusetts (Sept. 1) and New Hampshire (Sept. 8).
Ten Senate seats are open this cycle — four Democratic, six Republican — the most since 2012.
Seven Cook Political Report toss-up House districts had not yet held primaries as of early June.
Outside spending in Michigan’s Democratic Senate primary exceeded $65 million, roughly triple what the candidates raised themselves.
Runoff requirements and non-standard systems in Alaska, Washington, California and Louisiana mean the ballot is not final in every state until late September.

97 Days to the Midterms: The Senate and House Primaries That Haven’t Happened Yet