A trusted poll aggregator said Wednesday that Republicans now have a better than two-in-three chance of taking back the Senate in next week's midterm election.
FiveThirtyEight, the firm run by polling guru Nate Silver, said its latest model — which analyzed more than 1,500 polls about the election — says there is a 67.2 percent chance that the GOP will win a majority. To get there, Republicans will need to win a net six seats, which would give them 51 GOP senators.
That's the highest probability of a GOP win that FiveThirtyEight has given Republicans, and it follows a week in which many polls saw a shift toward Republican candidates around the country.
Back in mid-September, the firm gave Republicans a slightly better than 50 percent chance of retaking the Senate. But those chances have steadily increased over the last six weeks.
The firm now sees seven possible outcomes in which Republicans will control anywhere from 51 to 57 seats in the Senate. It says there is a 20.1 percent chance Republicans will hold 52 seats, and the chances drop as the number of GOP seats rises.
FiveThirtyEight estimates a 12.1 percent chance of a 50-50 tie in the Senate between Republicans and Democrats. However, that outcome would let Democrats keep control of the Senate, since Vice President Joe Biden would become the tie-breaking vote in terms of leadership decisions and possibly in legislative votes.
The firm says there's only about a 20 percent chance that Republicans will hold 49 seats or less.
Nate Silver famously predicted the outcome in the 2008 presidential race in 49 of 50 states. He moved his FiveThirtyEight blog to the New York Times, and later joined ESPN, where he and his team write data-driven analyses on sports and other topics.