Polls Show Democrats Extending Their Generic Ballot Lead

The chart above is from the Economist / YouGov Poll -- done between September 11th and 14th of a nationwide sample of 1,461 registered voters, with a 3.3 point margin of error.

The charts above are from the Marquette Law School Poll -- done between September 2nd and 9th of a nationwide sample of 864 registered voters (including 581 likely voters). The margin of error is 3.6 points for registered voters and 4.3 points for likely voters.