The most interesting poll released Tuesday in the fight for the Senate wasn’t actually a Senate poll. It was a national generic ballot poll — which party would you vote for in your congressional district? — from CNN/Opinion Research. The CNN survey gave Republicans a 49 percent to 45 percent lead among likely voters, as compared to a Democratic edge of 47 percent to 45 percent among registered voters.
With the new polling, the FiveThirtyEight model now has Republicans leading the generic ballot, our best measure of the national political environment, by 1.5 percentage points. It was closer to a tie when the model first launched last week.
Historically, the party out of the White House — that’s the Republicans this year — has led on the generic ballot by an average of about 5 percentage points on Election Day. Democrats have been bucking that precedent, but the latest polls hint that bright spot may be dimming. (The FiveThirtyEight model adjusts the generic ballot polling a touch toward the historical average, so the possibility that Democrats would lose some ground was already slightly baked into our forecast.)
The good news for Democrats is that they are holding their own in states President Obama won in 2012. Over the past week, polls have come out showing Democrats leading in Colorado and Iowa, and a survey published on Tuesday found the same thing in Michigan.
Public Policy Polling found the Democratic candidate for Senate, Gary Peters, leading Republican Terri Lynn Land 43 percent to 36 percent with all the candidates on ballot polled (and 45 to 40 percent in a one-on-one matchup). FiveThirtyEight now gives Peters a 71 percent chance of winning, up from 65 percent.
The problem for Democrats is that Republicans don’t need to win a single state that Obama won to seize the Senate majority. Recent polls have shown Republicans likely to pick up seats in Alaska, Arkansas and Louisiana. If the GOP wins these, plus either Kansas or North Carolina, then we’ll have a Republican-controlled Senate (Republicans are heavy favorites to win seats in Montana, South Dakota and West Virginia).
With the national environment inching toward the GOP, it’s easy to see how Republicans win in those ruby red states. The GOP’s odds of winning the Senate ticked down a bit on the Democrats’ strong poll in Michigan, but FiveThirtyEight still has Republicans with a 62.2 percent chance of taking control of the chamber.