This story has been updated
With less than nine weeks remaining until Election Day, control of the U.S. Senate remains in play, as Republicans hold meaningful leads in five states currently held by Democrats, with six more Democratic seats remaining in our "toss-up" category. Since our last update two weeks ago, new polls have nudged our polling averages in a slightly more Republican direction in the more competitive states, particularly Florida, Kentucky, California and Washington.
Remember that to win an absolute majority in the Senate, the Republicans need to gain at least 9 seats (although as several Pollster and HuffPost commenters have pointed out, a gain of 8 seats would leave the Democratic majority dependent on vote of not always reliable Joe Lieberman).
Currently, Republican candidates hold strong double-digit leads in four states now represented by Democrats: North Dakota, Arkansas, Indiana and Delaware. The Delaware margin assumes that Mike Castle wins next week's Republican primary. Democratic hopes there will brighten considerably should Republican Tea Party candidate Christine O'Donnell prevail, as two recent polls show she would trail Democrat Chris Coons.
Six seats currently held by Democrats remain in our toss-up category:
- In Colorado, our most recent trend estimate shows Republican Ken Buck with a slim 3.3 point advantage (46.1% to 42.8%), over Democratic Senator Michael Bennet, although the two most recent polls point in opposite directions: The most recent Rasmussen Reports tracker gives Buck a four-point lead, while a survey conducted by a bi-partisan team of campaign pollsters gives Bennet a 3-point advantage.
- In Washington state, two recent automated surveys by SurveyUSA and Rasmussen show Republican challenger Dino Rossi narrowly but not significantly ahead of Democratic Senator Patty Murray. Rossi's 1.9 point edge (49.7% to 47.8%) on our trend estimate is slightly improved, but leaves Washington very much in the toss-up category.
- California has also seen two new automated surveys in the last week from Rasmussen and SurveyUSA both showing Republican challenger Carly Fiorina deadlocked with Democratic Senator Barbara Boxer. Our trend estimate now shows Boxer with an advantage of less than one percentage point (46.8% to 46.2%), an edge that has narrowed roughly two points over the last two weeks.
- All of the recent pubic polling in Wisconsin comes from Rasmussen Reports, which has shown a deadlocked race between Senator Russ Feingold and his Republican challenger Ron Johnson. Johnson's less than one-point margin on our trend estimate (47.3% to 46.0%) mirrors those results.
- In Illinois, a new live-interviewer survey by the Chicago Tribune confirms the results of the most recent Rasmussen automated survey. Both show Democrat Alexi Giannoulias and Republican Mark Kirk tied. Our trend estimate gives Giannoulias a two-point edge (39.7% to 37.7%)
- In Nevada, two recent surveys by Mason-Dixon and Rasmussen both show Democrat Harry Reid with non-significant leads of 3 and 1 percentage points respectively. Our trend estimate gives Reid a 3.4 point advantage (48.6% to 45.2%), mostly because Reid has led nominally on 8 of 10 surveys conducted since July.
Of the seats currently held by Republicans, only Florida remains in our toss-up category, and there our trend estimate shows Republican Marco Rubio with a 3.1 point advantage over Republican-turned-independent Charlie Crist (37.1% to 34.0%) with Democrat Kendrick Meek running a distant third (16.6%)
Two week ago, our trend estimate put Kentucky in the toss-up category, but two new recent polls by SurveyUSA and Kentucky cable news channel CN2 put Republican Rand Paul leading Democrat Jack Conway by margins of 15 and 5 points respectively. Our trend estimate now shows Paul leading by 5.3 points (44.9% to 39.6%), enough to shift Kentucky to lean Republican.
All tallied, we currently show 48 seats leaning or currently held by Democrats (including the two independents that caucus with the Democrats), and 45 seats leaning or currently held by Republicans. Thus, control of the U.S. Senate rests on the outcome of the seven contests now now in the toss-up category: Colorado, Washington, California, Wisconsin, Illinois, Nevada and Florida.
UPDATE: The original version of this post misstated the leader on our Illinois Senate trend estimate.