ANALYSIS — Less than a month before Election Day, the House and Senate battlegrounds continue to take shape, with ratings changing in a dozen races. 

GOP strategists believe they’ve weathered the Democratic surge created by the Dobbs decision, which overturned abortion rights, and the national environment is returning to something closer to the GOP advantage of most of the midterm cycle. But the Republicans’ path to a majority in the House is still decidedly easier than it is in the Senate, in part because of the struggles of GOP Senate nominees in key states. 

In the House, the latest rating changes are a mixed bag for the two parties, signaling that there isn’t a dramatic shift in either direction. Republican prospects have improved in six races: California’s 27th and 49th districts, New York’s 17th and 22nd districts, Oregon’s 5th District and Texas’ 28th District. Democrats’ chances look better in four races: Alaska’s at-large district, Illinois’ 17th, Montana’s 1st and Ohio’s 9th. 

Overall, expect a Republican gain of eight to 20 seats. But the nominees are within a few points of each other in at least two dozen races. If late-deciding voters break for GOP candidates or if polling has failed to pick up a swath of Republican voters once again, then GOP candidates could overperform, resulting in bigger Republican gains. 

The fight for the Senate is close, as the GOP path to a majority is more narrow than expected. Republicans are feeling better about Pennsylvania, even though Lt. Gov. John Fetterman still has the edge against Mehmet Oz. With just a few weeks to go, the North Carolina and Ohio races are still close, causing a rating change toward Democrats in both races, even though Republicans are confident that undecided voters will break their way. 

Overall, our Senate projection remains Republicans +1 seat to Democrats +1 seat. Two of the three outcomes within that likely range would keep Democrats in control. For the second cycle in a row, control of the Senate could hinge on a Georgia runoff. This time it would be on Dec. 6. 

If polling is accurate, it could be weeks before we know which party controls each chamber. There could be a significant number of uncalled races on election night, and it will take time to finish counting ballots and resolve court challenges. A delay in certifying races could keep the majority in suspense for longer than usual.

Here are the latest rating changes:

Two Senate races shift toward Democrats

• North Carolina Senate (Open; Richard Burr, R), from Lean Republican to Tilt Republican
• Ohio Senate (Open; Rob Portman, R), from Likely Republican to Lean Republican

Six House races shift toward Republicans

• California’s 27th District (Mike Garcia, R), from Toss-up to Tilt Republican
• California 49th District (Mike Levin, D), from Likely Democratic to Lean Democratic
• New York’s 17th District (Sean Patrick Maloney, D), from Likely Democratic to Lean Democratic
• New York’s 22nd District (Open; John Katko, R), from Tilt Democratic to Toss-up
• Oregon’s 5th District (Open; Kurt Schrader, D), from Tilt Democratic to Toss-up
• Texas’ 28th District (Henry Cuellar, D), from Likely Democratic to Lean Democratic

Four House races shift toward Democrats

• Alaska’s At-Large District (Mary Peltola, D), from Tilt Republican to Toss-up
• Illinois’ 17th District (Open; Cheri Bustos, D), from Toss-up to Tilt Democratic
• Montana’s 1st District (Open; new), from Likely Republican to Lean Republican
• Ohio’s 9th District (Marcy Kaptur, D) from Tilt Democratic to Lean Democratic

Nathan L. Gonzales is an elections analyst with CQ Roll Call.