Gallup's tracking of the generic ballot for Congress finds Republicans leading Democrats by 5 percentage points among registered voters, 48% to 43%, and by 11- and 17-point margins among likely voters, depending on turnout. This is the third consecutive week the Republicans have led on the measure among registered voters, after two weeks in September when the parties were about tied.
The latest results are from Gallup polling conducted the past two weekends, Oct. 7-10 and Oct. 14-17, and based on interviews with more than 2,700 registered voters and more than 1,900 likely voters.
For Republicans to lead, or even be at parity with Democrats, on the generic congressional ballot indicates they are in a good position to win a majority of House seats in the upcoming elections. This is because of Republicans' typical advantage in voter turnout, which in recent years has given that party an average five-point boost in support on Election Day.
If the elections were held today and roughly 40% of voters turned out -- a rate typical in recent years -- Gallup's Oct. 7-17 polling suggests Republicans would win 56% of the vote -- 8 points greater than their support from registered voters, and 17 points ahead of Democrats, at 39%. If turnout is significantly higher, Republicans would receive 53% of the vote (a 5-point improvement over their registered-voter figure), and the Democrats, 42%.
The likely voter estimates at both turnout levels have been consistent over the past three weeks.