WASHINGTON — The country’s largest gathering of conservative activists on Saturday crowned Mitt Romney their top pick for the Republican Party nominee.

In a straw poll conducted at the annual Conservative Political Action Conference, Romney edged out Rick Santorum 38 to 31 percent, followed by Newt Gingrich at 15 percent and Ron Paul at 12 percent.

Romney acknowledged the straw poll victory in a tweet sent out after the results were announced.

“Honored to have won the CPAC straw poll,” Romney said in the tweet. “I’m heartened that so many friends here agree with me about the need for conservative change.”

Sponsored by the Washington Times, the straw poll was supplemented by a national survey to gauge the candidate preferences of conservatives at large. In that additional measure, respondents still favored Romney over Santorum, but by a slimmer margin — 27 to 25 percent.

Paul was the only GOP primary contender to skip the conservative confab this year, citing a campaigning schedule that would not allow him to appear before the youth-heavy CPAC crowd.

Indeed, 44 percent of this year’s straw poll respondents were students, many from Young Republicans chapters across the country, according to officials.

Paul won the straw poll by wide margins in 2011 and 2010. Last year, Romney trailed him in second place by seven percentage points.

Romney, Santorum and Gingrich appeared separately to speak to the crowd Friday, allowing CPAC attendees to soak in the contenders’ pitches before straw poll voting closed at 1 p.m. Saturday. Convention registrants were able to vote in person or online starting Thursday morning.

Florida Sen. Marco Rubio, who appeared on the convention’s main stage Thursday morning, easily won a separate straw poll asking CPAC attendees who they wanted as the eventual nominee’s running mate. In the national survey, Rubio tied New Jersey Gov. Chris Christie as respondents’ top choice for a Republican vice president.

This year’s straw poll attracted 3,408 voters, the first time participation decreased since 2008.

In a post-convention news conference, pollster Tony Farbizio told reporters the slight dip in straw poll turnout could be attributed to fewer campaigns coming to the annual gathering as the primary competition naturally thins.

Palin’s ‘perfect, perfect ending’

Saturday’s straw poll wrapped the three-day summit of conservatives at the Marriott Washington Wardman Park hotel.

After the straw poll results were announced, former Republican vice presidential candidate Sarah Palin delivered what was easily the convention’s most rousing keynote address. The former Alaska governor brought CPAC attendees to their feet by distancing herself from a beltway culture she claimed had become tainted by Obama’s “crony capitalism.”

“We know how to change that,” she said, co-opting a few buzzwords from Obama’s 2008 presidential campaign. “Oh, yes, we do. Oh, yes, we can. Hope and change? Yeah, you gotta hope things change.”

When hecklers began shouting Palin down about 10 minutes into her speech, the CPAC crowd began chanting “USA! USA! USA!” until hotel security approached the jeering audience members.

“See, you just won,” Palin told audience members as several hecklers were escorted out of the Marriott Ballroom.

It remained unclear whether the hecklers were part of Occupy DC, which maintained a consistence presence on a sidewalk outside the hotel throughout the conference.

Nonetheless, Palin delivered an Occupy-targeted message in her address, suggesting the protesters to set their sights on a different target in the nation’s capital: The White House.

“You’re occupying the wrong place,” she said. “You’re protesting the wrong thing.”

Despite Romney’s just-announced straw poll victory, Palin only offered vague hints at how she views the current field of GOP primary contenders.

She did, however, advise the four candidates’ campaigns to avoid the type of back-and-forth attacks that could damage the GOP in the general election.

“I believe that the competition has gotta keep going,” she said. “But let’s make sure this competition brings out the best in our party.”

During the post-convention news conference Saturday, American Conservative Union Chairman Al Cardenas praised Palin’s speech as one of the best he’s heard from the political celebrity.

His comments, however, left the book open on a broader concern about the direction of the Republican primary once CPAC attendees fan out across the country Sunday morning.

“I was… a little concerned going into this about the expected feistiness of a very competitive presidential primary, and how we’re going to leave here,” he told reporters. “Are people going to leave here in herds of supporters of one candidate or another? But I thought Sarah Palin was the perfect, perfect ending to a great conference.”