Real Clear Politics currently gives Democrats 46.9 percent and Republicans 40.3 percent in the generic congressional ballot (“If the elections for Congress were being held today, which party’s candidate would you vote for in your Congressional district?”), a 6.6 percentage point lead for the Democrats.
This sounds pretty good for the Democrats, but historically a 6.6 percent lead is not close to enough, given that a Democrat is president and some voters like to balance the presidential and congressional parties.
More specifically, we can plug the data in to these graphs from Joe Bafumi, Bob Erikson, and Chris Wlezien:
The paper accompanying this graph was among the first public predictions of a Democratic takeover in 2006.
Bafumi, Erikson, and Wlezien’s analysis doesn’t go back 300 days before the election, but if we take the liberty of extrapolating . . . The current state of the generic polls gives the Democrats .469/(.469+.403) = 54 percent of the two-party vote. Going to the graph, we see, first, that 54 percent for the Democrats is historically on the low side and that the expected Democratic vote — given that their party holds the White House (the blue points on the graph) — is about -2%, or a 52-48 popular vote win for the Republicans.
Would 52 percent of the popular vote be enough for the Republicans to keep their House majority? I haven’t looked at the data lately, but my guess is yes.
It’s still early — and there’s a lot of scatter in those scatterplots — but if the generic polls remain this close, the Republican Party looks to be in good shape in 2014.