Senate Races Tighten, Future Control Up for Grabs

A few months ago, the future makeup of the U.S. Senate seemed more certain: Democrats had all but conceded Joe Manchin’s West Virginia seat and faced long odds in Montana to return Jon Tester to office, while holding on to all their incumbents.

Such a result would put GOP control in the Senate, regardless of the outcome of the presidential race. However, as the election approaches, races are tightening, making the outcome less predictable.

One possibility is that Republican Senate seats in Texas or Florida (or both) could flip to Democrats. The last poll in the Florida Senate race, conducted by The Hill/Emerson College with 815 likely voters from Sept. 3-5, showed Republican incumbent Rick Scott up by just one point over his Democratic opponent Debbie Mucarsel-Powell. In the Florida Senate RCP Average, he leads by 4.3 points, but more polls in the next month could signal a closer race, similar to the Emerson poll.

In Texas, three polls over the past month and a half have all shown Ted Cruz leading by multiple points against his opponent, Collin Allred. One from late August by the University of Texas had Cruz up by eight, one from mid-September by the Texas Hispanic Policy Foundation had Cruz up by three, and the latest poll from The Hill taken from Sept. 22-24 had Cruz up by four. His lead in the Texas Senate RCP Average is five points, similar to Scott’s, but the frequency of polling in Texas makes Cruz’s lead seem more stable.

If Republicans lose either of these races and Democrats hold their leads in swing states, the Senate could be split 50-50 after the November elections. This would mean that the vice president of the winning presidential candidate would cast the tie-breaking vote in the Senate.

However, Democrats’ hold on swing state seats isn’t guaranteed either. In Ohio, a Hill/Emerson College poll in March found that Democratic Sen. Sherrod Brown led Bernie Moreno by five points, but the latest Hill poll from early September found Brown only up by two. Other recent polls, from NYT/Siena and Bowling Green/YouGov, have Brown up by four points, leading to an Ohio Senate RCP Average of Brown ahead by 3.3 points.

In Pennsylvania, Democratic incumbent Bob Casey Jr.’s lead against Republican challenger David McCormick has narrowed to four points in the Pennsylvania Senate RCP Average, down from 7.6 points in late August. The latest three polls from Emerson College, Trafalgar Group (R), and Atlas Intel also show the race within one or two points, indicating that McCormick could take the lead in the final month before the election.

A similar trend is seen in Wisconsin, where Democrat incumbent Tammy Baldwin’s lead in the Wisconsin Senate RCP Average has shrunk from 6.7 points in late August to 3.5 points now. The latest polls show some disagreement: Trafalgar and Atlas Intel have Baldwin up by just two and one point, respectively, while an NYT/Siena poll from Sept. 21-26 has Baldwin up by seven.

In Michigan, the Senate race has also tightened. Neither candidate is an incumbent, and Democrat Rep. Elissa Slotkin’s lead has narrowed from five points in late August to three points now in the Michigan Senate RCP Average. An Atlas Intel poll even found that former Republican Rep. Mike Rogers led by five points, though other polls from around the same time show Slotkin still ahead.

In two other swing state Senate elections, the Democrats’ leads appear more solid. In Nevada, Democrat incumbent Jacky Rosen leads by 8.5 points in the Nevada Senate RCP Average, and in Arizona, Democrat Rep. Ruben Gallego leads by 7.8 points in the Arizona Senate RCP Average.

If all current RCP Averages hold, Republicans will win the Senate 51-49, as shown in the RCP Senate No Toss-Up Map. However, if there are changes in the two Republican-held Senate seats in Florida and Texas, or if Republicans manage to flip seats in swing states where Democrats’ leads are weakening, the Senate’s balance could shift from predictions made just a few months ago.