What we learned about Senate control from primary results

The Senate Battleground

The eight races below will make or break Senate control this November. But with primary season coming to an end, what can we learn from results in each of these states? Read more to find out.

Alaska

Alaska's unique primary system gives us greater insight into who will win the general election than any other state. That's because in Alaska, every candidate is placed on the same ballot, and the top four vote-getters advance to the general election. This means the November election essentially serves as a runoff of the primary.

Our forecast currently shows this state leaning toward Republicans. However, if these results persist into the general election, Democrats would flip Alaska for the first time in decades.

Georgia

Because Incumbent Democratic Senator Jon Ossoff is running for reelection, no Democrats challenged him in the primary. Thus, Georgia didn't have a Democratic Senate primary, though Republicans did. If Democrats held a Senate primary, the numbers below likely would have been even better for them.

Our forecast currently characterizes this state as likely for Democrats. That characterization perfectly aligns with the results of this statewide primary. Not only is a win of this magnitude realistic, but it would also be monumental for future Democratic ambitions in the state.

Iowa

With Incumbent Republican Senator Joni Ernst retiring, both parties held primaries to fill this open seat. In fact, both the Democratic and Republican primaries for this Senate seat were competitive, drawing more extensive, more accurate turnout data than would typically be available.

We are forecasting Iowa as likely for Republicans in the November election, though the primary results suggest a far more competitive race.

Maine

Because Incumbent Republican Senator Susan Collins is running for reelection, no Republicans challenged her in the primary. Thus, Maine didn't have a Republican Senate primary, though Democrats did. If Republicans held a Senate primary, the numbers below likely would have been even better for them.

Our forecast shows Maine leaning towards Republicans this November. Though Democrats appear to be winning in a landslide based on primary results, Republicans are expected to outperform these metrics since they didn't have a primary.

Michigan

In the Great Lakes State, Republicans opted to run the same candidate for Senate as in 2024. He drew no challengers. Thus, Michigan didn't have a Republican Senate primary, though Democrats did. If Republicans held a Senate primary, the numbers below likely would have been even better for them.

Our forecast characterizes the Michigan Senate race as leaning towards Democrats. Based purely on primary turnout, Democrats appear much more enthused to vote than Republicans, though the lack of a Republican primary could be making these results more favorable to Democrats than they will be in November.

North Carolina

Incumbent Republican Senator Tom Tillis opted not to run for reelection. Thus, with no incumbent on the ballot, both Democrats and Republicans held Senate primaries in North Carolina. With both parties holding primaries, the results provide an accurate understanding of what may happen in November.

We are currently forecasting this state as likely for Democrats. The results of this primary precisely reflect that characterization—the November results could very well mirror these numbers.

Ohio

Though he's never won a Senate election, Republicans cleared the primary field for Incumbent Senator Jon Husted, who was appointed after J.D. Vance left his seat to serve as vice president. Democrats, however, held a Senate primary. If Republicans had done so as well, the numbers below likely would have been even better for them.

Our forecast currently characterizes this state as leaning towards Republicans, matching the turnout numbers from this primary. With Democrats so optimistic about this state, they probably would have wanted to see more enthusiasm in this primary. This result could foreshadow Democrats falling short here this November.

Texas

Democrats and Republicans both held nail-biter primaries for Incumbent Republican John Cornyn's Senate seat. With an unprecedented turnout, the primary election results not only showcase voter enthusiasm but could also foreshadow the eventual results this November.

We are currently forecasting this state as leaning towards Republicans. Yet, even with Republicans having an ultra-competitive primary, they lagged behind Democrats in turnout for the first time in decades. This could be one of the closest states in November.

What does this amount to?

It's important to note that this is not a perfect science. While the primary turnout numbers seem like reasonable general election results in states like Alaska, Iowa, Ohio, and Texas, states like Michigan and Maine will almost certainly be closer than these numbers suggest.

Still, there's an argument to be made that real, tangible votes from the same electorate, voting for the same candidates, just months before the general election, is a much stronger indicator of what will happen in November than, say, run-of-the-mill polling or fundraising numbers.

Ultimately, if primary turnout perfectly predicted the outcome of these eight battleground races this November, Democrats would narrowly flip Senate control, gaining a 51-49 majority.