Republicans hold the largest lead on the generic Congressional ballot in Gallup’s polling history. The party of Reagan and Lincoln holds a 10-point lead over Democrats, 51-41%.

The Republican leads of 6, 7, and 10 points this month are all higher than any previous midterm Republican advantage in Gallup’s history of tracking the generic ballot, which dates to 1942. Prior to this year, the highest such gap was five points, measured in June 2002 and July 1994. Elections in both of these years resulted in significant Republican gains in House seats.

That point needs to be stressed: Republicans now hold a larger generic advantage than in 2002, after the 9/11 attacks, or in 1994, right before the Republican Revolution. That’s how bad things are for Democrats in 2010.

But wait, there’s more! Gallup actually polls registered voters instead of likely voters. What’s the difference? Registered voters tend to be more favorable towards Democrats than likely voters. So the actual results in November could be worse for Democrats than even this poll suggests.