House Republicans were catapulted into the majority with a broad base of support but will need to work "very hard" to sustain it, according to David Winston, a GOP pollster who advises Speaker John Boehner (Ohio).

In November, Republicans captured 63 House seats and control of the lower chamber. They did that by appealing to traditionally Democratic constituencies, Winston said Thursday at a breakfast hosted by the Third Way, a centrist think tank. 

"Republicans won women in this election" by one point — "in the previous majority we never won them," he said, citing exiting polling from last November. "Suburban voters minus 2 [percent] to plus 13; Catholics minus 10 to plus 10 [percent]; senior citizens [evenly split] to plus 21." 

The GOP also increased its share of the Hispanic vote from 30 percent in 2006 to 38 percent in 2010, he added. "This is a broad majority coalition."

Winston said Democrats sought to motivate their base voters by prioritizing healthcare reform over job creation and painting the GOP as poor stewards of the economy. But as a result, the GOP was able to win independents by a large margin.

Republicans had lost independents by 18 percent in 2006, when the Democrats retook the House majority, he said. "This election, it was plus 19. That's a huge shift and that's where the majority came from."

The challenge for Republicans now to is sustain that broad support in a cycle when they have a presidential primary stirring up the conservative base and the Tea Party movement playing in congressional nominating contests.

It won't be easy, Winston admitted.

"Sustaining and continuing a majority coalition, it's just very hard work," he said. "It means you've got to get people who don't necessarily always agree going in the same direction. Whether it's Nancy Pelosi or John Boehner, it's just hard."

Republicans, who ran on a message of "where are the jobs?," need to instill confidence in voters that they're effectively handling economic issues. "If that confidence isn't there, it's a real problem for Republicans," he said.