Statistician Nate Silver on Sunday said Republicans are now slight favorites to win at least six seats and take control of the Senate.
Silver wrote in a blog post that Republicans “have great opportunities in a number of states." At this point, he is rating West Virginia, South Dakota, Montana and Arkansas as “clearly” leaning toward the Republicans.
In an interview that aired on ABC’s “This Week,” Silver said the GOP has a 60 percent chance of winning control of the Senate and a 30 percent chance to win it big. The Democrats, by contrast, have only a 40 percent chance of holding onto their majority, he said.
Arkansas is one state where Republicans have been "pretty consistently ahead in the polls,” he said. “We give them a 70 percent chance of winning in Arkansas. Louisiana is about 55 percent. North Carolina is a purple state so that’s about as 50-50 as it gets.”
Rep. Tom Cotton (R) is challenging incumbent Democratic Sen. Mark Pryor in Arkansas. Rep. Bill Cassidy (R), among others, is running against incumbent Democratic Sen. Mary Landrieu in Louisiana. A slew of GOP candidates are running to unseat incumbent Democratic Sen. Kay Hagan in North Carolina.
The GOP has a 45 percent chance to win in Alaska and Michigan, 35 percent chance in Colorado and 30 percent chance in Iowa, Silver said on “This Week.”
Silver predicts Republicans will pick up six Senate seats, but they could win as many as 11.
New Hampshire might not be in play, however, despite former Massachusetts Sen. Scott Brown (R) recently entering the race, Silver said.
“We think the Republican opportunity in New Hampshire is a little overhyped. Scott Brown was extremely popular in a different state four years ago.”
Silver’s last forecast, in July 2013, concluded the race for Senate control was a toss up.
“The Democrats’ position has deteriorated somewhat since last summer, with President Obama’s approval ratings down to 42 or 43 percent from an average of about 45 percent before,” Silver writes in his latest post at ESPN's fivethirtyeight.com.
“Furthermore, as compared with 2010 or 2012, the GOP has done a better job of recruiting credible candidates, with some exceptions,” he added.
Silver’s blog at The New York Times accurately predicted every state in the 2012 presidential election.
Rep. Tom Cole (R-Okla.) on "This Week" said the GOP's expanding playing field in recent months supports Silver's latest predictions.
Obama also didn't win the states in 2012 that Silver identified as being swing districts or leaning toward the GOP.
"Most of the places that Silver ticked off are red states that the president lost poorly — lost badly in the last election," Cole said.
“This is a snapshot in time,” Rep. Keith Ellison (D-Minn.) cautioned on “This Week.” “I think this is going to motivate our base,” he added.
— This report was first published at 10:48 a.m. and last updated at 2:12 p.m.