Miami (CNN) Jeb Bush , a scion of the most recognizable family in Republican politics who fashioned an image as a sober-minded conservative truth-teller while governor of Florida, is running for president.

Bush made his formal announcement Monday afternoon here in his adopted hometown during an appearance at Miami Dade College. His candidacy comes after a week-long European tour and months of intensive behind-the-scenes political maneuvering that erased long-standing doubts about his White House ambitions.

Arguing that the country is on "a very bad course," Bush told supporters in Miami that the nation had a decision to make.

"The question for me is what am I going to do about it," he said Monday afternoon. "And I've decided: I'm a candidate for president of the United States of America."

Bush, standing calmly in front of a podium without a blazer, was at one point interrupted by protestors wearing yellow shirts with letters that read, "Legal Status Is Not Enough," who calling for immigration reform. Departing from his prepared remarks, Bush shot back that as president, he would pass "meaningful immigration reform" rather than solving the problem via an executive order.

Bush enters a crowded field of candidates, becoming the 11th GOP contender to jump in the race. In his homestate, his most threatening competitor is Sen. Marco Rubio: The two are currently competing for money in the Sunshine State and support from high-profile figures here.

During his event, Bush showed off how he had already secured endorsements from key Florida Republicans. Members of the Florida state cabinet sat near the front and were recognized before Bush's speech. Attorney General Pam Bondi, Agricultural Commissioner, Adam Putnam and Chief Financial Officer Jeff Atwater and former Florida Sens. Mel Martinez and George LeMieux all were in attendance.

Without mentioning Rubio by name, Bush emphasized in his speech that voters should support a candidate with executive experience -- a governor, not a senator -- in 2016.

​"As our whole nation has learned since 2008, executive experience is another term for preparation, and there is no substitute for that," Bush said. "We are not going to clean up the mess in Washington by electing the people who either helped create it or have proven incapable of fixing it."

Monday's launch sets John Ellis Bush, 62, the second son of former President George H.W. Bush and younger brother of former President George W. Bush, on a potentially historic course that would confirm his family's standing as America's preeminent political dynasty, rivaled only by the Kennedys in their fame and cross-generational power.

But it's clear Bush's campaign sees his famous family can be both a blessing and a curse. Looking on as Jeb Bush jumps into the race Monday was matriarch Barbara Bush, the former first lady and already mother of one former president, as well as a slew of other siblings, his children and more extended family.

Absent? The two former presidents, who Bush only mentioned once obliquely in his speech.

"If Jeb wins, we have the most successful dynastic line in American political history, bar none," said historian Rick Perlstein, author of multiple books tracing the history of the Republican Party. "I don't think you see this level of accomplishment across the generations with the Kennedys. You have a senator in Prescott Bush, and the son becomes president, then the grandson is also president, and now you throw in a former governor who might be a president."

Bush hinted Monday that he knew he would have to win the nomination himself this primary season -- rather then run solely on his lineage.

"It's nobody's turn. It's everybody's test. And it's wide open, exactly how a contest for president should be," Bush said Monday.

No front-runner

But for all his name recognition, Bush isn't entering the race as a clear front-runner. A national CNN/ORC Poll released earlier this month found him virtually tied at the top of the field with Sen. Marco Rubio, a fellow Floridian. Behind them, 10% of those polled said they planned to support Wisconsin Gov. Scott Walker and former Arkansas Gov. Mike Huckabee.

When matched against Democratic candidate Hillary Clinton, Bush trails 51% to 43%.

Bush has suffered a few stumbles in the months leading up to Monday's announcement, most notably when he struggled to answer questions about his brother's invasion of Iraq, a line of questioning many Republicans said he should have anticipated. And he's gone out of his way to avoid declaring himself a presidential contender -- until now -- so he could keep raising money for the Right to Rise super PAC backing his candidacy.

With his brother's presidency still deeply polarizing in the mind of the electorate, and foreign policy once again rising as a top public concern, his campaign will test the nation's appetite for another Republican named Bush. The late-May CNN/ORC Poll found that 56% of respondents said his connection to two former presidents would make them less likely to support his campaign.

JUST WATCHED Jeb and George W.: Comparing the brothers Bush Replay More Videos ... MUST WATCH Jeb and George W.: Comparing the brothers Bush 01:43

Should Clinton capture the Democratic nomination, a 2016 campaign between Bush and Clinton would undoubtedly be clouded by questions about legacy, nepotism and the vitality of a political system seemingly dominated by a pair of powerful families with close ties to wealthy elites in Washington and on Wall Street.

Those anxieties would unfold against the backdrop of an America confronting dramatic shifts in demographics, economic behaviors and generational tastes, challenging the maxim that presidential campaigns are about the future rather than the past.

Before that dynamic comes to pass, the pragmatic Bush must first overcome the more pressing challenge of securing the GOP nomination, a steep hill to climb for a self-styled reformer who has called for an ever-more-conservative Republican Party to temper its rhetoric, change its thinking and expand its appeal to nontraditional voters. In pre-campaign visits to the early nominating states of Iowa and New Hampshire, Bush promised to run a "joyful" campaign that capitalizes on optimism rather than fear.

'Much more positive'

"I don't know if I would be a good candidate or a bad one, but I kinda know how a Republican could win, whether it's me or somebody else, and it has to be much more uplifting, much more positive," Bush said at a December event for business leaders hosted by the Wall Street Journal.

The Republican nominee, Bush said at the time, must be willing to "lose the primary to win the general without violating your principles."

In fact, he strikes that optimistic tone in one of several YouTube videos his campaign released on the cusp of his launch.

"We led, we reformed, we got results. That's what's missing from Washington. The D.C. crowd talks about what's wrong with America; I see what's right," he said in the latest released video, entitled "The Greatest Century."

Bush proclaimed Monday "the greatest time ever to be alive in this world."

For a cerebral policy maven who has rankled conservatives with his full-throated support for comprehensive immigration reform, the education standards known as Common Core and "revenue enhancement" in pursuit of a federal budget deal, it was an early and defining statement that will be challenged by the bruising gantlet of Republican caucuses and primaries that select the party's nominee.

Already tagged with the dreaded "moderate" label by some conservatives and fending off questions about his brother, Bush opens the campaign with even less good will among Republican voters than Mitt Romney had at the outset of the 2012 race, polls show.

Even with a steady base of support, Romney — a business-friendly candidate like Bush who was the leading choice of the Republican establishment — confronted skeptical primary voters by dodging questions, contorting his arguments and staking out controversial positions on immigration and abortion rights to appease the party's restive grass-roots base, only to see his past statements spook him throughout his ill-fated general election bid.

Bush will try to avoid a similar fate against a field of younger candidate that includes several uncompromising conservatives who entered politics in the polarizing heyday of the tea party movement.

"Most candidates have enough challenges answering voters' questions based on their own records, let alone the records of two presidents who share their name," said Ben Domenech, publisher of The Federalist, a conservative web magazine. "It's unfair, but that's the way it is."

But when offered a chance to address some of the major decisions made by his brother during his presidency, Bush waffled.

Iraq

While traveling this spring to raise support for his forthcoming campaign, Bush struggled to address basic questions about George W. Bush's policy legacy, particularly the war in Iraq. In May, when asked by Fox News if he would have invaded Iraq "knowing what we know now," Bush said he "would have." He later said he misheard the question. But when Fox gave him another opportunity to address the question, he declined to provide an answer: "I don't know what that decision would have been -- that's a hypothetical."

"But the simple fact was, look, mistakes were made, as they always are in life. This is not a -- foreign policy," Bush added. "So we need to learn from the past to make sure we're strong and secure going forward."

In a preview of the GOP primary battle to come, Bush's Republican competitors quickly pounced on him for not answering the question. The backlash prompted Bush to tackle the question again.

"Knowing what we know now, ... I would not have engaged," Bush said on May 16. "I would not have gone into Iraq."

JUST WATCHED The Bush family and Iraq Replay More Videos ... MUST WATCH The Bush family and Iraq 01:44

"Jeb can argue he had a more conservative record as governor, but that just may not count much with an electorate that remembers his father for a tax hike and his brother for two wars," Domenech said. "Jeb will have to battle those ghosts in order to get the nomination. He'll also have to navigate a field with multiple candidates who have every incentive to turn him into a creature of the past and brand themselves as the way of the future, to attack him as a Common Core-pushing technocrat, as soft on gay marriage, or as a lover of amnesty."

Bush advisers predict he will actually benefit from dim expectations over time. They argue that Bush's record as governor — he called himself a "head-banging conservative" when he first sought the office unsuccessfully in 1994 — is actually more right-leaning on social issues, taxes, education reform and gun rights than many voters realize.

Democrats hope to highlight that resume, and have already begun reminding the public of Bush's controversial involvement in the legal battle over Terri Schiavo, in which the then-governor used the power of the state to keep the brain-damaged woman alive on a feeding tube over the wishes of her husband. Bush's efforts in the case not only infuriated Democrats who saw the governor as a social crusader, they rankled small-government conservatives who chafed at government intervention in a private family matter.

Path to nomination

With a crowded roster of candidates, Bush may not need to win over most Republican primary voters, and only a slice of wary conservatives, to secure the nomination. The successful Republican campaigns of Romney in 2012 and John McCain in 2008, both favorites of the GOP establishment, relied on consolidating a plurality of moderate voters, and allowing the rest of the field to cannibalize the conservative vote in primary and caucus states.

"The battle to see who can attain the greatest degree of purity on the right can result in a fractured fight that splits that support across so many candidates," said Republican strategist Kevin Madden, who advised Romney's two campaigns in 2008 and 2012. "It's like a Nascar race where five or six cars bunched up against the wall spin out, allowing one car to slingshot past them right at the turn towards the checkered flag."

Bush, though, will face a thornier path than Romney, who had no viable GOP opponent in the race to win over centrist, business-friendly Republicans. In the 2016 campaign, there are multiple GOP contenders — like Rubio, Walker, New Jersey Gov. Chris Christie and former Texas Gov. Rick Perry — who are, for now, palatable to mainline Republicans.

But Bush has been busy tapping his family's network of wealthy donors since he began his behind-the-scenes campaign last winter, giving him an edge over his foes in the struggle for support among Republican power brokers in Washington and New York. And since 1964, no Republican has won the party's nomination without the blessing of the party establishment.

Moving quickly last December in what his aides called a "shock and awe" campaign to lock in support from donors, Bush boxed out other establishment-friendly hopefuls like Christie and Rubio from padding their early war chests and boosting their standing with the media. No GOP candidate has raised more money than Bush — much of it going to an allied super PAC — precious funds that will be spent on staff, advertising and establishing a state-of-the-art campaign.

Genial but sometimes given to fits of impatience — "He doesn't suffer fools well," one supporter recently confided to CNN — it remains a pressing question whether Bush, who last ran for office as Florida governor 13 years ago, is temperamentally suited to the staccato-burst combat of today's fast-moving campaign life.

Social media age

Unlike fresher-faced rivals like Walker, Rubio, Christie, Kentucky Sen. Rand Paul and Texas Sen. Ted Cruz, Bush has never won an election, let alone a primary, in a polarized social media age that prizes pitched rhetoric over thoughtful discourse.

But in a rush of behind-the-scenes work that began late last year as he inched closer to a campaign, Bush and top advisers Sally Bradshaw and Mike Murphy undertook the process of shoring up his weak flanks, hiring a brigade of younger political operatives and consulting with digital and data experts in Silicon Valley to build the kind of tech-savvy operation that helped President Barack Obama win two national elections.

They recruited an Iowa-based GOP operative fixated with voter targeting, David Kochel, who helped Romney to an impressive near-win in the 2012 Iowa caucuses, and a communications director, Tim Miller, respected for his relationships with a younger generation of political reporters, many of whom were still in middle school when Bush last won an election.

Kochel was expected to serve as campaign manager, but in a last-minute staff shake-up just days before Bush's presidential announcement, the campaign-in-waiting announced that instead, Kochel would remain as an adviser and focus on early voting states. Instead, the operation tapped a 39-year-old Danny Diaz, who has worked on the past three Republican presidential efforts.

The eleventh hour reshuffling exposed conflicts in Bush's early operation that pitted old advisers who have been with Bush since his days as governor with new strategists and staff. As his campaign launch date neared, it also appeared that his super PAC would not reach it's early fundraising goals.

Bush wrote off the criticism when asked about changing his campaign apparatus so close to the announcement.

"It's June, for crying out loud, so we've got a long way to go," Bush said.

Supporters say his willingness to analyze his own faults, process criticism and calmly reason his way through political complexities signals Bush's readiness for the Oval Office.

"Jeb's never been surrounded by 'yes people,'" said Ana Navarro, an informal adviser to Bush from Florida. "Not even in his private life. His friends and advisers have no qualms about disagreeing with him and telling him so. He doesn't shut down debate. He'll listen. Doesn't mean he'll change his mind. But he'll listen and take it in."