Former Arkansas governor Mike Huckabee speaks at the Conservative Political Action Committee annual conference in National Harbor, Md., on March 7. Huckabee campaigned for the Republican presidential nomination in 2008. (Susan Walsh/Associated Press)

If Mike Huckabee is going to make a serious run for the Republican presidential nomination, he will have to do something he was unable to do in 2008: raise millions of dollars and build a sprawling national campaign to complement the well of support he has among evangelicals and grass-roots activists in early primary states.

The former Arkansas governor, whose sudden departure from Fox News has ramped up speculation about his political future, would immediately bring to the 2016 contest a high profile from his TV work and goodwill with the GOP’s most socially conservative voters, but he would be dogged from the start by questions about his organizational and fundraising abilities.

“You’re going to need $150 million to win the nomination, and probably $75 million to get you through Iowa, New Hampshire and South Carolina,” Ed Rollins, a former Huckabee adviser, said in an interview. “That means 200 to 300 fundraising events and a vast, focused apparatus. Mike didn’t have that last time, and he still has to prove he can develop one.”

Huckabee’s challenge is one shared by an emerging faction of nearly a dozen Republicans — including Gov. Bobby Jindal of Louisiana and former Hewlett-Packard chief executive Carly Fiorina — pondering how to mount bids that could be sustained beyond the race’s initial stages and compete with the fundraising prowess of more prominent potential contenders, such as former Florida governor Jeb Bush and New Jersey Gov. Chris Christie.

The movement in the GOP contrasts with the Democratic Party, whose ranks are rapidly coalescing around Hillary Rodham Clinton as their standard-bearer. Other potential Democratic candidates, such as former Virginia senator Jim Webb and Maryland Gov. Martin O’Malley, have failed to gain much traction.

The candidate from the crowded pack of Republicans who is most able to raise significant money and develop on-the-ground heft in the coming year may have the best shot of lasting through what could be a bruising and drawn-out nominating fight, according to several GOP strategists interviewed Sunday.

“The main problem for everybody is ensuring you have adequate financing,” said former Pennsylvania congressman Bob Walker (R), who advised former House speaker Newt Gingrich’s 2012 presidential campaign. “It’s hard to get it, though, until things really begin to play out. While you wait, you’ve got to create a narrative that separates you from the rest of the field and have your fundraising strategy in order.”

For now, addressing the financial expectations will be among Huckabee’s first tests. After briefly surging to the fore of Republican presidential politics when he won the Iowa caucuses in 2008, Huckabee watched his campaign quickly fade as he struggled to keep his ads on the airwaves and bring on staff in key states.

Huckabee is not expected to begin fundraising aggressively before a formal decision to run — and not until after his upcoming book tour for “God, Guns, Grits, and Gravy,” a 272-page manifesto that will serve to reintroduce him to those who rallied behind his last campaign.

Meanwhile, Bush is already tapping the party’s wealthiest financiers. On Wednesday, Bush will raise money for his political action committee in Greenwich, Conn., Hearst Connecticut Newspapers reported Sunday, with “an assemblage of relatives and political allies with ties to his father and brother,” both former presidents.

A senior Huckabee aide, who was not authorized to comment publicly and spoke on the condition of anonymity, sought Sunday to counter suggestions that the former governor will find it difficult to raise the necessary funds.

The aide said Huckabee’s team anticipates the need to raise about $50 million by the time of the Iowa caucuses in early 2016, with the money divided between the campaign’s budget and a super PAC, and said Huckabee has done much work to make that a reachable goal.

“There are people who have come to us talking big numbers,” the aide said. “People who want to do super-PAC stuff, people who want to bundle. That doesn’t mean we’re going to get them all, but there is a level of security on our side that the financial support is going to be there this time.”

David Lane, a Christian political strategist who is friendly with Huckabee, said in an interview Sunday there are “serious people” looking at a Huckabee candidacy, though he declined to name those possible donors.

Outside of Huckabee, a growing number Republicans have been eyeing the 2016 campaign as an unusual opportunity. While Bush and Christie are well-regarded by many donors on Wall Street, they are not dominant party figures poised to become the clear front-runner. Sensing an opening, senators, governors and tea party favorites, such as Maryland neurosurgeon Ben Carson, have been working for months to cultivate relationships and jockeying for the support of influential players.

Like Huckabee, Govs. Jindal, Rick Perry (Tex.), Scott Walker (Wis.), John Kasich (Ohio) and Mike Pence (Ind.) and Sens. Rand Paul (Ky.) and Ted Cruz (Tex.) are Republicans with steady presence in the news media who have expressed interest in possibly jumping into the 2016 race, along with Fiorina, former Pennsylvania senator Rick Santorum and Rep. Peter T. King (N.Y.), among others. How to turn their name identification and various achievements into the buzz and capital needed to compete is a puzzle all are considering.

Edging onto Huckabee’s turf, Jindal will meet Tuesday with pastors in Iowa for a series of closed-door meetings. Paul has been keeping in touch with investors in Silicon Valley who may be interested in supporting a slightly contrarian Republican. Pence has traveled to Israel to speak on foreign policy and stayed close to the billionaire industrialist brothers Charles and David Koch. Cruz has developed a massive e-mail list after leading congressional quarrels over health care and immigration.

Huckabee was unavailable for an interview Sunday. In December 2013, he told The Washington Post that asking for donations was a part of the process he detested. “Begging people for money was not pleasant, and fighting off total distortions about one’s record is not pleasant,” he said. “But as far as the campaign itself, that was exhilarating. I love that part of connecting with people and the ability to do that.”

In 2008, Huckabee raised about $16 million, mostly from individual contributors, according to the Center for Responsive Politics. Nearly 40 percent of that total came during the three months before the January 2008 Iowa caucuses, when Huckabee, buoyed by his debate performances and a warm reception from the base, began to climb in GOP opinion polls.

Huckabee’s political action committee, Huck PAC, was active in 2014, raising more than $2 million and spending nearly as much.

In the 2012 contest, the most expensive presidential race on record, Republican nominee Mitt Romney had about $1 billion spent on him by his campaign, the Republican National Committee and the super PAC Restore Our Future, according to the Federal Election Commission.

Spencer Zwick, who ran Romney’s fundraising operation in 2012, said in December: “It’s just as hard to raise $100 million for the primary as it will be to raise $1 billion for the general. . . . In the primary, every contribution you get, you are asking for it. You’re working a lot harder for those dollars.”

Huckabee, 59, spent part of November holding meetings with powerful GOP donors in Las Vegas, New York and California, gauging their interest in being bundlers and asking for pledges of five-to-six-figure donations to his aligned organizations. In December, he held meetings in Little Rock and Destin, Fla., near his Gulf Coast home, to discuss his potential campaign.

He also faces fresh obstacles from the right after playing the role of conservative foil to Sen. John McCain (R-Ariz.) and other more centrist Republicans in 2008. Since the former Baptist preacher was last on a ballot, Common Core, a program of national education standards he once supported, has become anathema to tea party Republicans. Huckabee said in 2013, for instance, that the standards were “near and dear to my heart.” He has since walked back those comments and called the program “toxic.”

Another likely hurdle for Huckabee as he solicits donations: scattered antagonism among the GOP’s fiscally conservative donors who find Huckabee’s record on taxes and spending to be lacking.

Former Indiana congressman David McIntosh, who is president of the Club for Growth, a free-market advocacy group, said in an interview Sunday that most donors he knows think Huckabee should be running in the Democratic presidential primary. He also said that the group, which hounded Huckabee in 2008 with critical ads and news releases, would do the same in 2016. A revised white paper on Huckabee is in the works.

“He’s a big-government Republican who dramatically increased spending and increased the state sales tax” in Arkansas, McIntosh said. “Republican donors are going to look at that record and say, ‘We care a great deal about economic issues, and we need a stronger candidate.’ ”

A Huckabee representative was unavailable Sunday to respond. When Huckabee ran in 2008, he frequently talked about how he turned a budget shortfall in Arkansas into a budget surplus. He also noted that he had to work with a Democratic state legislature.

Part of Huckabee’s book tour, scheduled to begin this month, will bring him back to Iowa, where his advisers have said he will reassure conservatives on education and other hot topics. In late January, Huckabee will appear at the Iowa Freedom Summit in Des Moines. He was invited by the gathering’s host, Rep. Steve King (R-Iowa), who is one of the GOP’s most prominent hard-liners on immigration. Bush, a vocal supporter for a path to legalization for illegal immigrants, declined King’s invitation to speak.

Departing his Fox News program on Saturday with dramatic flair, Huckabee said, “I say goodbye, but as we say in television, stay tuned.” In a note on Facebook the same day, Huckabee wrote, “I won’t make a decision about running until late in the spring of 2015, but the continued chatter has put Fox News into a position that is not fair to them.”

Huckabee had hosted an eponymous show on the network for more than six years, blending his populist conservative politics with discussions on music, culture and faith. The perch made him a celebrity among the cable channel’s viewers and provided him with a hefty paycheck that enabled him to construct a beachfront mansion in Florida.

Rollins maintains that Huckabee, despite the hurdles ahead, could eventually soar, much as he did in late 2007 before Iowa’s first-in-the-nation caucuses.

“He remains the most charismatic candidate around,” Rollins said. “The problem for us in 2008 was that every morning we were wondering if we had enough money to fly to the next spot. If he wants to go the distance, he can’t find himself in that position again.”

Karen Tumulty contributed to this report.