The seven-percentage-point edge for Democratic congressional candidates, nationally, contrasts with ties or Republican leads in most Gallup polls leading up to the 2010 midterm elections. However, the Democratic advantage is not as large as those they enjoyed in the 2006 and 2008 congressional election cycles — each of which produced a Democratic majority in Congress. The Democrats averaged a 10-point lead over Republicans among registered voters in the year prior to the 2008 elections and an 11-point advantage leading up to the 2006 elections, with individual polls showing them ahead by as much as 23 points…

Gallup also asked registered voters how a Tea Party endorsement would affect their likelihood of voting for a congressional candidate. The effect is nearly 2-to-1 negative, with 42% saying they would be less likely to vote for such a candidate versus 23% saying they would be more likely. About a third say it would make no difference or are unsure.