The charts above were made from information contained in AP-GfK surveys taken in the last year and a half. The latest AP-GfK Poll was done between May 16th and 19th of this year, where a random national sample of 1,354 adults (with a margin of error of about 3 points).
Many political pundits are still saying the Republicans will retain control of the House of Representatives. If they do, it will be because of some effective gerrymandering done by the GOP after they won control of many state governments in 2010 -- because as these charts show, Democrats outnumber Republicans in the United States.
Those who self-identify as Democrats are about six points more than those identifying themselves as Republicans (32% Democrat and 26% Republican). And it gets worse for the Republicans if you add in those who say they lean toward one party or the other -- going up to a nine point deficit for the Republicans (with 43% Democrats and 34% Republicans).
If the Independents stay home on election day, and only Democrats and Republicans vote -- it could be a very good day for Democrats. And considering the very low opinion of the 113th Congress that most voters have, it could be a good day for Democrats even if large numbers of Independents turn out to vote.
It also might not be too bad if the voters vote on issues rather than party labels. The chart below, from the same survey, shows the public thinks the GOP would do a better job on defense and the budget. The choice over who would be better to run the government and fix the economy (a surprise since it was Republicans who trashed the economy) was within the poll's margin of error. The Democrats were thought to do a better job when it came to health care, immigration, marriage, abortion, promoting equality, and perhaps most important of all, the personal concerns of voters.