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The Tea Party movement emerged on the U.S. political scene with much fanfare, but nearly three years after it began, its influence in the 2012 presidential election has yet to stand out.

The grassroots conservative movement was successful in pulling in hundreds of thousands of Americans into the nation's capital and organizing rallies across the country to bring attention to the nation's fiscal plight. It was also credited with helping propel to power many new, unusual candidates in the 2010 mid-term elections.

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But the Tea Party has been less visible when it comes to the 2012 elections, with many questioning whether it wields the same kind of influence it once did. There have been no rallies in Washington, D.C., recently and the movement has been overshadowed by the Occupy Wall Street movement.

Newt Gingrich and Mitt Romney, the top two contenders for the GOP nomination, have both supported policies on health care reform and economic issues that go against the very core principles of the Tea Party movement.

There's also little unity within the movement. Though some Tea Party leaders have endorsed Gingrich, saying that there's no perfect candidate, one of the movement's shining stars, Sen. Rand Paul, today warned that doing so could crumble the movement.

"While conservatives and limited-government activists did, indeed, make great strides in 2010, those could easily be set back by nominating someone with a different set of ideas and values in 2012," warned the senator from Kentucky, whose father, Rep. Ron Paul, is also a candidate. "Gingrich is not from the Tea Party. He is not even a conservative. He is part of the Washington establishment I was sent to fight."

An Associated Press-GfK poll conducted in mid-August - after the debt showdown in Congress - found that unfavorable views of the Tea Party jumped to 32 percent, up 10 percentage points from November 2010. Only a quarter of those polled considered themselves a part of the conservative movement, the lowest number ever in Associated Press-GfK's polling.

Meanwhile, the presidential candidates who rose to the top on the back of Tea Party support - Rep. Michele Bachmann and Gov. Rick Perry - have seen their popularity drop sharply. Both Gingrich and Romney are establishment candidates that the Tea Party has so derided in the past.

Tea Party leaders say the movement isn't dying, but acknowledge that it's changing and the overt show of support has declined from its heyday.

The movement "has grown up. We have learned that there is more to being involved in politics than simply getting up there screaming as loud as we can," said Judson Phillips, founder of the Tea Party Nation, which held the first and only Tea Party convention in February 2010, featuring Sarah Palin. "Sometimes that does have a place, and it was crucial in the birthing of this movement, but now the important thing for us to do is to be involved in the campaign."

Phillips has endorsed Gingrich despite the former House Speaker's close ties to corporate giants and once support of such anti-Tea Party principles like the individual mandate, which requires people to purchase health insurance .

"We are not looking for a perfect candidate," he said. "We are looking for the best guy running."

Others challenge the claim that the movement's influence is waning, saying that though the Tea Party may not be as visible in the streets and in the media as before, it's been successful in getting people to talk about its core principles of fiscal responsibility, limited government and free markets.

"The reality is, what's happened is, the ideas of the Tea Party movement have ingrained themselves in American consciousness," said Mark Meckler, co-founder of the Tea Party Patriots, which doesn't officially endorse any one candidate. When one listens to Romney, "he's saying he's for fiscal responsibility, lesser government, less regulation, following the constitution, that we need to support the job creators in the free market. That's our core principles."

But even Tea Party leaders admit that their influence at the presidential level may not be quite as hefty and that the focus of this conservative grassroots movement will be on local and state elections next year.

"What the Tea Party is going to focus on a lot in this election cycle is … Democrats and Republicans running in congressional races that the Tea Party believes will hold whoever the president is accountable," said John O'Hara, author of "A New American Tea Party" and vice president of external relations at the Illinois Policy Institute.

Perhaps the biggest shift in the movement is that it's less of a national force - as it was when the health care law was being debated - and more of a regional entity, experts say.

Its influence has diminished severely in states like Massachusetts, where Sen. Scott Brown - once the darling of the movement - has now backtracked from his staunch support and has made several votes that have irked those conservatives who helped get him elected.

In Maine, where Tea Party activists helped lift Gov. Paul LePage to power, the state's highest ranking official has run afoul of his own Republican party. He's been publicly rebuked for calling some protestors "idiots" and saying that the NAACP can "kiss my butt" after declining to attend a Martin Luther King Day celebration. The former incident prompted a rare op-ed by Republican state senators criticizing LePage for "picking a personal fight."

The Tea Party's influence is also questionable in key swing states, observers say.

"I think it's doomed not to extinguish its opponents and achieve dominance over the entire country because its support varies strongly regionally," said Colin Woodard, journalist and author of "American Nations: A History of the Eleven Rival Regional Cultures of North America." "The decay of its support in certain key regional cultures is crippling to the Tea Party's influence not only in the Northeast and Upper Midwest but also in key swing states like Ohio and Pennsylvania."