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Mike Huckabee said Saturday there would be no sequel to his surprisingly strong 2008 White House bid, in which he won the Iowa Republican caucus and finished second in the primaries to Sen. John McCain.

"All the factors say go, but my heart says no," Huckabee, who was considered the GOP frontrunner in several national polls, said on his Fox News Channel show.

The show is normally prerecorded before it airs at 8 p.m. ET, but Huckabee saved the last 10 minutes of tonight’s broadcast to make his announcement live.

"The past few months have been times of deep personal reflection," Huckabee said. "Even though I wasn't actively establishing a campaign organization or seeking financial support to run again, polls have consistently put me at or near the top to be the Republican nominee."

"But I know that under the best of circumstances, being President is a job that takes one to the limit of his or her human capacity," he continued. "I can't know or predict the future, but I know for now my answer is clear and firm:  I will not seek the Republican nomination for President this year."

Huckabee said others probably thought about a presidential bid more than he did.

"I had not done much toward a race because my life was filled with work that I truly love here at Fox News, doing radio commentaries on my daily Huckabee Report on 600 radio stations, traveling the country for speaking engagements, and helping good conservative, pro-life candidates who were running for office," he said.

Donald Trump delivered a message after Huckabee's decision to opt out.

"A lot of people are very happy that he will not be running, especially other candidates, so Mike enjoy the show," Trump said.  "The ratings are terrific. Good luck."

Huckabee led polls early in the 2012 season, even winning a South Carolina county straw poll in April. Supporters took to Facebook to express their dismay.

"Mike- I respect your decision but I am very disheartened," a contributor to Huckabee's Facebook page wrote.

Before his announcement Saturday night, Huckabee hadn't shared his decision with his closest advisers.

Many of those advisers predicted Huckabee wouldn't run.

Ed Rollins, who was Huckabee's national campaign chairman for the 2008 campaign, said he expected this decision after Huckabee had broken off communications with him about a week ago.

“He’s not going to run,” 2008 Huckabee campaign director Ed Rollins told Fox News before the announcement. "About a week ago he broke off communications, which tells me he's not going to run.”

But as late as Saturday morning, Huckabee wouldn't tip his hand even when asked about Rollin's statement.

"I haven't even told my executive producer of the show tonight what the decision is," Huckabee said on "Fox and Friends."

"That's kind of refreshing because for the last several months they've all known," he said when asked about predictions by political insiders that he wouldn't run. "They've either known for sure that I was or for sure that I wasn't, when even I wasn't sure. Now that I'm sure they admit they don't know."

In the end, Huckabee decided that he didn't want to abandon the media empire that he has built since his failed presidential bid four years ago. In addition to his TV show, Huckabee hosts a nationally syndicated radio program, gives paid speeches around the country and has even launched a series of animated videos for children on American history.

The talk show is the centerpiece of Huckabee's enterprises, which have made the one-time Baptist preacher from Hope, Ark., and 10-year governor a wealthy man with a $2.2 million beachfront home under construction in Florida. Huckabee, 55, and his wife moved their residency and voter registration to the state last year.

Rollins and other advisers have said Huckabee could enter the race with a frontrunner status he didn't have as a former governor fresh out of office in 2008. But another Huckabee run would bring renewed scrutiny over his support of some tax increases in Arkansas and his record on clemency -- including commuting the sentence of a man who later killed four Seattle-area police officers.

Huckabee demurred when asked on Fox whether he felt an obligation to run.

"The obligation is to love your country and serve it the best way you can. If that's being a candidate, then yes. If it's maybe in another role, maybe that's it," Huckabee said

Fox News producers Serafin Gomez and LA Holmes contributed to this report.