But top contenders Massachusetts Gov. Mitt Romney and former House Speaker Newt Gingrich have not elicited the amount of enthusiasm in voters that Obama did in 2008, at least so far. But as Duffy points out, President Obama isn't attracting the same amount of excitement this time around either.
"Obama in 2008 won Indiana. Obama's not going to win Indiana again," she says. "I think you are looking at a slightly different map than you were in 2008."
Duffy says control of the body is likely going to come down to a handful of toss-up seats, including the already closely watched Massachusetts contest, which pits Republican Sen. Scott Brown against Harvard Professor and former Obama Administration official Elizabeth Warren, a Democrat.
"(It's) going to be just epic," Duffy says. "In terms of money spent and attention paid is going to be pretty remarkable."
- See the GOP's top Senate targets of 2012.
- Read GOP rivals go into attack mode.
- Check out photos of the 2012 GOP candidates.
Corrected on 12/13/2011: An earlier version of this article omitted the words "cash on hand" in a sentence; this version has been corrected.