Dems on Defense as GOP Gains Ground in Senate Races

This year, Democrats are playing defense in Senate races, with all the most likely seats to flip currently held by Democrats. As the election nears, several races are tightening, putting Republicans within reach of gaining more Senate seats than anticipated.

The states that have shifted most in the Republican challengers' direction are Wisconsin and Pennsylvania. Both feature similar races, with former businessmen challenging longtime incumbent Democratic senators in swing states. A few months ago, both Republican challengers were trailing by more than 5 points, but now the races are much closer.

In Wisconsin, the latest InsiderAdvantage poll, conducted Oct. 26-27 among 800 likely voters, shows Republican Eric Hovde leading Democrat incumbent Tammy Baldwin by 1 point. Since Sept. 30, Baldwin's lead in the Wisconsin Senate RCP Average has shrunk from 3.6 points to just 0.7.

In Pennsylvania, the same InsiderAdvantage poll shows Republican David McCormick tied with incumbent Democrat Bob Casey. Similarly, Casey’s lead has dropped from 4 points to just 1.2 over the past month in the Pennsylvania Senate RCP Average.

Ohio's Senate race has also tightened significantly, though it’s not a swing state in the presidential election. Despite Trump leading by 7 points in the Ohio RCP Average, Republican challenger Bernie Moreno trails Democrat incumbent Sherrod Brown by 1 point in the Ohio Senate RCP Average.

In Michigan, another close state, Democrat incumbent Debbie Stabenow is retiring, leaving the field open for new candidates. Currently, Democrat Rep. Elissa Slotkin leads former Republican Rep. Mike Rogers by 2.4 points in the RCP Average.

In two other swing states, Arizona and Nevada, Republican candidates trail by wider margins. In the Nevada Senate RCP Average, Democrat incumbent Jacky Rosen leads Republican Sam Brown by 5 points, and in Arizona, Democratic Rep. Ruben Gallego leads Republican Kari Lake by 6.3 points.

A few months ago, Republicans were expected to win the Senate with a narrow 51-49 majority, flipping Montana and West Virginia from Democrats, who currently hold a 51-49 majority. However, with Wisconsin, Pennsylvania, Ohio, and Michigan tightening, Republicans have a chance to pick up additional seats, potentially increasing their majority and making it easier to retain control in 2026.

Democrats have slim chances to pick up unexpected seats in Montana and Texas. In Montana, Democrat incumbent Jon Tester trails Republican challenger Tim Sheehy by 6.5 points in the RCP Average. The Texas Senate race is closer, but Republican Ted Cruz still leads Democrat Colin Allred by 4.2 points in the Texas Senate RCP Average.

If Democrats manage to flip one of these seats and hold the others, the Senate could end up tied at 50-50, leaving the deciding vote to the vice president. In that case, the Senate’s balance would depend on who wins the presidency.