Former Rep. Thomas M. Davis III, the architect of previous Republican campaign successes, says outer-suburban voters eager to place a check on President Obama and Democrats are swinging back to the GOP and will power a Republican resurgence in New England, while aiding GOP "tsunamis" in Virginia, Colorado and Iowa.

Mr. Davis, the current president of the Republican Main Street Partnership, a group of the party's more moderate lawmakers, told reporters Wednesday that the GOP has had its best-ever year of recruiting candidates for congressional elections, which has helped put so many seats into play.

He said Democrats are having a tough time reaching a balance of keeping regular voters happy while also appeasing the liberal voters who surged to the polls in the 2008 election.

"Those are the problems Democrats have coming in. The surge voters right now, they're asleep. And the outer suburbs, the South, the mountain states, I think you can look for Republican tsunamis," Mr. Davis said. "You're going to have big years."...