Newt Gingrich is a one-state wonder who is unlikely to play out as the conservative alternative to Mitt Romney sought by some tea party activists, one of the movement's driving forces said Sunday.

"I don't think Newt will be able to replicate that magic moment in South Carolina," said Dick Armey, chairman of the conservative grassroots group FreedomWorks, on CNN's "State of the Union."

Romney, meanwhile, "continues to work along at a steady pace, and we are left with a dilemma that we are not going to get a reliable, small government conservative out of this nominating process," lamented Armey, a former Republican leader in the U.S. House.

His comments came the day after Gingrich placed second after Romney in Nevada's caucuses, which gave the former Massachusetts governor his second straight win of the primary and caucus season and third overall.

FreedomWorks has long opposed the possibility of a Romney White House, warning last summer that its supporters may stay home in November's general election if Romney is the Republican nominee.

In the early primary and caucus states, Romney polled low among those who self-identified as tea party supporters, while Gingrich drew much of the momentum for his South Carolina primary victory from activists within the grassroots movement.

Recent primaries show the tables have turned. In entrance and exit polls from the Florida and Nevada contests, Romney climbed considerably in support among the tea party base, garnering 39% of the voting bloc in Nevada to Gingrich's 30%.

Also on the CNN program Sunday, Family Research Council president Tony Perkins said Romney was gradually making headway among evangelical voters, another conservative bloc.

"They're warming to him," Perkins told CNN Chief Political Correspondent Candy Crowley. "But he still has a long way to go."

Despite Romney's progress among tea party supporters and social conservatives, Armey said his group would work to elect conservatives to Congress instead of focusing on the presidential race.

"We'll build a legislative wall," Armey said. "We'll either be walling a Republican president in, or walling a Democratic president out."

Ultimately, however, Armey said he would support Romney if the former governor ends up competing against Obama in the fall.

"We would rather have a Republican president that's not fully the guy we adore wanting our affections than a Democrat president who despises us and covets the affections of our mortal enemies on public policy," he said.