Polls show that the Republican nominee has gained ground in a key Senate race, Wisconsin — and Republicans have put another Senate race, in West Virginia, squarely into play. But strong polling for Democrats in two Pacific Coast states, California and Washington, have somewhat offset these gains, and Republicans are only modestly more likely to take control of the Senate than they were a week ago.
The FiveThirtyEight forecasting model assigns Republicans an 18 percent chance of emerging with at least 51 Senate seats after the Nov. 2 elections; this is up slightly from a 15 percent chance last week. During an average simulation run, Republicans finished with control of 47.6 Senate seats, up from 47.1 last week. The simulation counts possible outcomes in which Senator Lisa Murkowski succeeds in her write-in bid in Alaska as a Republican win.
Republican chances are significantly improved in two states. The first is Wisconsin, where three polls show the Republican, Ron Johnson, leading the incumbent Democrat, Russ Feingold, by margins of 6 to 11 points. Prior polling had shown the race to be roughly a tie.
Although Mr. Feingold’s approval ratings have been decent in some surveys and the state has leaned Democratic in recent elections, polls in Wisconsin show a large “enthusiasm gap” favoring Mr. Johnson, a businessman from Oshkosh who has been endorsed by several Tea Party groups. This may be one place where a Tea Party candidate is helping Republicans, as polls had shown other potential Republican candidates in Wisconsin with more tepid numbers. Mr. Johnson is now a 80 percent favorite, according to the model.
The other state to show a big move in Republicans’ favor is West Virginia, where a new survey, from Public Policy Polling, gives the Republican there, John Raese, a 3-point lead. West Virginia remains somewhat underpolled, although three recent surveys from Rasmussen Reports had given the Democrat, Gov. Joe Manchin III, leads of 5 to 7 points, which is enough for the model to still consider him a slight favorite. But Mr. Raese’s chances of winning the state are up to 28 percent, from 10 percent last week.
Tom Jensen, of Public Policy Polling, has an insightful article on the dilemma that West Virginians face. They are quite happy with their governor, but equally unhappy with President Obama. Voters who liked Mr. Manchin but disliked Mr. Obama were tending to vote Republican in Mr. Jensen’s poll.
Were it just for these two states, Republican chances of taking over the Senate — which suffered in last week’s forecast because of the victory of Christine O’Donnell in the Delaware primary — might have improved fairly significantly. But Democrats have made gains in another key state, California, which cuts against some of the equity that Republicans might have gained.
In California, there have been four polls released since last week’s forecast, all of which show material gains by the Democratic incumbent, Barbara Boxer. Ms. Boxer is now a 78-percent favorite to prevail in California, up from 58 percent last week. Although some of the California polls, like the one from Public Policy Polling, shows a voter sample that seems quite favorable to Democrats, younger voters may be more inspired to vote in California than elsewhere in the country because of the presence of a ballot initiative, Proposition 19, which would legalize possession of marijuana for personal use. The ballot initiative is favored to pass by most polls.
Democrats had made gains in last week’s forecast in Washington, and their chances have improved slightly further there with another poll showing the incumbent Democrat, Patty Murray, with a lead. She is now about a three-to-one favorite over the Republican, Dino Rossi.
Another state on the Pacific Coast, Alaska, is now a three-way contest among Joe Miller, the Republican, Scott McAdams, the Democrat, and the incumbent, Lisa Murkowski, who is running as a write-in. Although Ms. Murkowski’s chances may be difficult to assess from conventional polling, the model’s best guess is that her write-in bid has about a 16 percent chance of prevailing. However, because Ms. Murkowski has promised to rejoin the Republican conference if elected, we are treating wins for her as Republican wins.
Mr. McAdams has about a 3 percent chance of victory by the model’s estimate. It is plausible that Mr. McAdams’s chances will improve in future polling given the reconciliation between Ms. Murkowski and Senate Republicans on Wednesday — she was allowed to keep her position as the senior Republican on the Energy and Natural Resources Committee — which may make it more difficult for her to appeal to the more liberal half of the Alaskan electorate. Still, the Republican, Mr. Miller, is a clear favorite there.
Two other races merit watching: Connecticut and the special election here in New York, where the Republican candidate has some plausible chances. But considering Connecticut to be a tossup, as some analysts have done, is not warranted on the basis of the evidence. The Democrat there, Richard Blumenthal, has a lead in the high single digits on the basis of most polling, and — equally importantly — there are very few undecideds in the race. Although leads like that can be overcome late in a race, it is uncommon.
Over all, the Senate picture is more fluid than a week ago, and somewhat better for Republicans. But were the election held today, they would probably not win the contests in California and Washington, and that would prevent them from accumulating enough seats to take over the Senate (even if they were to win other close races like Illinois, Nevada and West Virginia). Thus, Republicans probably need some additional momentum to claim the Senate, whether in individual states like California or nationally.