With Just One Week to Election Day, These GOP Senate Seats Are Most Likely to Flip Blue

Just seven days remain until Election Day, and a significant number of Republican-held Senate seats look set to flip blue for Democratic challengers.

The current Senate is controlled by 53 Republicans, while there are 45 Democrats and two independents who caucus with their Democratic colleagues. But forecasts and polls suggest that is likely to change after November 3. Just one Democrat-held seat—that of Senator Doug Jones of Alabama—looks set to flip red, while nine GOP senators appear to be in danger of losing their seats, according to the Cook Political Report's analysis.

Based on a close look at the most recent polls, at least three Senate Republicans are at a clear disadvantage against their Democratic challengers, while two other races appear to be leaning toward Democrats. GOP Senators Cory Gardner of Colorado, Martha McSally of Arizona and Susan Collins of Maine are all trailing their opponents. Republican Senators Thom Tillis of North Carolina and Joni Ernst of Iowa are in close races, with current polling averages slightly favoring their Democratic rivals.

U.S. Capitol
The U.S. Capitol, where the Senate convenes, on October 26. At least three Senate Republicans are at a clear disadvantage against their Democratic challengers, while two other races appear to be leaning toward Democrats. OLIVIER DOULIERY/AFP/Getty

In Colorado, Gardner is up against the state's former governor, John Hickenlooper. Two October polls show the Democratic contender ahead by 9 percentage points and 8 percentage points, respectively. In the first poll, carried out by KUSA/SurveyUSA, Hickenlooper was supported by 48 percent of likely Colorado voters, and Gardner was backed by just 39 percent. The other survey, by the University of Colorado/YouGov, showed similar results, with the Democrat backed by 48 percent of likely voters, as opposed to 40 percent who supported the GOP incumbent.

The Real Clear Politics average of recent Arizona polls shows McSally with a deficit of 4.2 percentage points against the Democratic candidate, retired astronaut Mark Kelly. A poll carried out by CNBC/Change Research this month showed Kelly ahead by double digits (11 percentage points), while polling by the conservative Rasmussen Reports had the Democrat up by just 2 percentage points.

Collins trails her Democratic opponent, Sara Gideon, the speaker of the Maine House of Representatives, by an average of 4.2 percentage points, according to Real Clear Politics. The Republican was down by 7 percentage points in an October poll carried out by Pan Atlantic Research. But the Bangor Daily News showed a closer race, with Gideon leading by just 1 percentage point in a poll conducted from September 25 to October 4.

In what appears to be a closer contest, Tillis is down by an average of nearly 2 percentage points against his Democratic opponent, Cal Cunningham, a retired military officer and former member of the North Carolina Senate. An October poll by the Trafalgar Group shows Tillis leading by 2 percentage points, but an October survey by CBS News/YouGov shows Cunningham ahead by 6 percentage points. Other recent polls show Cunningham ahead or in a tied race.

Ernst is in a similar position in Iowa. Democrat Theresa Greenfield leads by an average of nearly 2 percentage points. But two recent October polls, by Emerson College and The New York Times/Siena, showed Ernst ahead by 1 point. Three other October polls put Greenfield in the lead by a range of 2 to 5 percentage points.

The Cook Political Report rates the races by GOP Senators Kelly Loeffler of Georgia, David Perdue of Georgia, Steve Daines of Montana and Lindsey Graham of South Carolina as "toss-up" races. But a closer look at the polling averages compiled by Real Clear Politics suggests that Republicans are still favored to win—with the exception of Loeffler.

In Georgia, Loeffler was appointed in 2019 to serve until a special election could be held to replace Senator John Isakson, who resigned. The winner-takes-all race is expected to go to a runoff, as there are multiple candidates, with none currently polling above or even close to 50 percent. It's not currently possible to assess how the runoff could play out—although polling suggests it will be between Loeffler and Democrat Raphael Warnock.

In order for Democrats to firmly take control of the Senate, they would need to gain at least four seats—giving them a slim majority of 51 to 49. However, if Joe Biden wins against President Donald Trump, Democrats could control a 50-50 split Senate. In the case of ties, the vice president—which would be Democratic vice presidential nominee Kamala Harris in this scenario—would cast the deciding decision on evenly split votes.