The State, Tracy Glantz, Associated Press
Former Florida Gov. Jeb Bush speaks at commencement exercises for The University of South Carolina in Columbia, S.C., on Monday, Dec. 15, 2014. It marks the Republican leader's second visit in three months to the state that will host the 2016 presidential primary season's first contest in the South.
Marco has a lot of respect for Gov. Bush, and believes he would be a formidable candidate. However, Marco's decision on whether to run for president or re-election will be based on where he can best achieve his agenda to restore the American Dream — not on who else might be running. —Alex Conant, a spokesman for Rubio

TALLAHASSEE, Fla. — Former Florida Gov. Jeb Bush announced Tuesday he will "actively explore" a campaign for president, an early move that could pre-empt some other Republicans with White House aspirations in the bidding for big donations and public support.

In a holiday message posted on his Facebook page, the son and brother of Republican presidents said he had discussed the "future of our nation" and his own prospective bid for the White House with members of his family over the Thanksgiving holiday.

"As a result of these conversations and thoughtful consideration of the kind of strong leadership I think America needs, I have decided to actively explore the possibility of running for president of the United States," Bush wrote.

Bush's announcement is sure to reverberate throughout Republican politics and begin to sort out a field that includes more than a dozen potential candidates, none of whom have formally announced plans to run. It overshadowed comments from former New York Gov. George Pataki, who told the New York Daily News in a story published Tuesday he was "very seriously" considering a bid.

Should Bush ultimately decide to run, he could tap into his family's vast political network, and his campaign would attract strong support from the same donor pool that other establishment-minded Republicans would need. A Bush campaign also could affect the plans of several Republican governors, including New Jersey's Chris Christie and Wisconsin's Scott Walker.

"I don't think it will affect their willingness to run, but it will affect to some extent their ability to raise money," said Fred Malek, the finance chairman of the Republican Governors Association.

A Bush candidacy also has the potential to affect Florida Sen. Marco Rubio, who came up through that state's politics as a strong Bush supporter and is considering whether to seek re-election to the Senate or run for president in 2016.

"Marco has a lot of respect for Gov. Bush, and believes he would be a formidable candidate," said Alex Conant, a spokesman for Rubio. "However, Marco's decision on whether to run for president or re-election will be based on where he can best achieve his agenda to restore the American Dream — not on who else might be running."

But Brian Ballard, a Tallahassee lobbyist who was a top Florida fundraiser for the past two Republican nominees, said he expected most major donors in the state would commit to Bush.

"He freezes everyone out," Ballard said. "Florida will be off- limits to other presidential candidates should Jeb decide to run."

Kristy Campbell, a spokeswoman for the 61-year-old Bush, said he had not yet made a final decision. She said he would announce that decision next year "after gauging support" for a run.

"This is a natural next step and represents a new phase of his consideration process," Campbell said.

That phase will include an expansion of Bush's political operations. He said Tuesday he will start his own leadership political action committee in January, which will allow him to raise money that can pay for his travel and the infrastructure of a nascent campaign, including office space and some broad polling.

Tuesday's statement was the most definitive signal that Bush plans to try and become the third member of his family to serve as president. In a TV interview this past weekend, he said he felt he "would be a good president," disclosed that he was writing an e-book about his time as governor that would come out in the spring, and promised to release about 250,000 emails from his time in office.

During his two terms as Florida governor, Bush pushed for large tax cuts, overhauled Florida's education system and led an effort to eliminate race-based policies in college admissions and state spending.

Since leaving office, Bush has continued to advocate for more changes to the nation's schools, including the adoption of new education standards known as Common Core. Those standards have drawn the ire of conservatives who view them as a federal intrusion into local classrooms. Bush has continued to call them critical to overhauling the country's education system, while seeking common ground with opponents by saying states should be allowed to develop their own education programs.

Richard Schwarm, a former Iowa state Republican Party chairman, said that while Bush holds some positions that don't sit well with some GOP activists, "I think they'll realize his honesty and integrity on speaking out on his mind shows he has the courage of his convictions."

"Iowans will give him a serious look," Schwarm said. "And that's all candidates can ask for. It's up to him to make the sale to Iowans."

Associated Press writer Philip Elliott contributed to this report from Washington. Beaumont reported from Des Moines, Iowa. Follow Gary Fineout on Twitter: http://twitter.com/fineout