"We felt that Governor Christie, a crowd favorite at previous CPACs, was not particularly deserving this year," Cardenas wrote to the Washington Post. "I have said that CPAC is like an 'All Star' game for conservatives. Even players that have great careers in baseball don't make it to the All Star game every year. I hope he earns an invitation next year. But, everyone must keep in mind that we are not the Republican Party - we are conservatives."

McDonnell's most likely transgression, though Cardenas has not confirmed it, is his recent support for a transportation package that stipulated a sales tax hike. Meantime his attorney general, Ken Cuccinelli - a longtime favorite of the Tea Party - opens CPAC's festivities this morning.

But it's not as simple as the Tea Party versus the Republican establishment, Bonjean said. The number of shades on the conservative continuum and the subtleness between them show a far more fractured movement.

On the CPAC lineup, Palin, once an electric trailblazer for the Tea Party, can be lumped not with the far-right grassroots types, but with firebrands like Donald Trump, the real estate mogul-turned-reality TV star set to speak Friday morning. "Those speakers show that the organization is looking to grab sensationalistic headlines through speakers that will likely say over-the-top statement in front of hundreds of reporters, rather than have a real, serious discussion about the direction of the party," Bonjean said.

Then there's Paul, who's expected to sweep the conference's straw poll in the footsteps left by his likeminded libertarian father, former Texas Rep. and three-time presidential candidate Ron Paul. In his first year in the Senate, the younger Paul founded the Tea Party caucus, a nod to his hands-off government roots. His nearly 13-hour filibuster against drone strikes on U.S. soil last week, though, drew praise from Republicans and Democrats across the board who lauded him for returning to regular order on the floor.

But there's also the "moderate," "centrist," "evolving" Republicans, like Romney, but perhaps modeled best by former Gov. Jon Huntsman, who as expected did not receive an invitation to speak. Unable to find his footing in the 2012 presidential primary, the pro-civil unions candidate who believed in climate change - two points he opened with during an unsuccessful appearance at an election-related Florida CPAC event - dropped out of the race and levied an unofficial boycott on the party.

This year, the conference's decision to ban the gay Republican group GOProud has drawn criticism from conservatives saying the movement is heading in the wrong direction on social issues.

Despite the countless gradations, though, there's an inarguable divide on CPAC's agenda between those active and future leaders who have carved their positions in stone, and those who have made clear their desire to work toward ending the years-long Washington gridlock.

On one side: Former senator and almost-presidential nominee Rick Santorum, whose willfulness on social issues attracted a following to counter Romney's momentum; former Rep. Allen West, a Tea Party darling who campaigned for a recount for weeks after his loss in November; and Jenny Beth Martin, co-founder of the Tea Party Patriots who the day after the general election lambasted Romney as "a weak moderate candidate, hand-picked by the Beltway elites and country-club establishment wing of the Republican Party."