In previous cycles, we've had soccer moms and NASCAR dads as the voting demographic that tipped elections one way or another.
Next year it may be seniors.
Seniors broke heavily for Republicans in 2010 and they are usually a disproportionate voice in midterm elections because they're more likely to vote.
Here are the key takeaways from the poll:
In Republican battleground districts, the vote is deadlocked among seniors and the Democratic candidate has gained 5 points among this group since early last summer.
In Democratic battleground districts, Democratic incumbents lead by 14 points — 51 percent to 37 percent — among seniors.
Most interesting is that Democracy Corps has now seen this trend in its last three national surveys and calls it "a sea change."
It's especially important because seniors are among the most reliable voters to get to the polls.