The Senate race to watch is the battle in New Hampshire between Republican Scott Brown and Democratic incumbent Sen. Jeanne Shaheen, Republican National Committee Chairman Reince Priebus told MSNBC's "Morning Joe."
"Scott Brown is closing fast. And I think that if I'm talking to our people at events, I tell people, 'Look, watch New Hampshire,'" Priebus said Tuesday. "If you see him close or winning in New Hampshire, which I think he's going to do, I think you're going to see Republicans pretty happy."
Once considered a long shot, Brown, a former Massachusetts senator, has closed the gap in the race.
Most polls show Shaheen slightly ahead, with one putting Brown in the lead by 1 percentage point.
In the Wisconsin governor's race, Priebus said "truckloads of money from national unions and soft money organizations" was the reason why the race was tight between Republican Gov. Scott Walker and Democratic opponent Mary Burke. He predicted Walker would prevail, and stressed turnout would be an important component.
"It's really a matter of the ground game there. I really think that Scott's doing great," he said. "You have both parties in Wisconsin that are about the two best parties in the country, as far as turnout."
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In races across the country, Priebus said Democratic candidates had gotten better, but "Republicans have improved to the mountains and back," due to an emphasis by the GOP on garnering early votes.
"Basically, the point here is that the Republican party has gotten its act together when it comes to early and absentee ballot voting. I still think we've got a ways to go when it comes to the ground game in technology. But we're doing a lot better, clearly," he said.