Former Florida Gov. Jeb Bush speaks in Detroit on Feb. 4. (Paul Sancya/AP)

Jeb Bush acknowledged that he may not be a flashy speaker or make the loudest arguments. But the Republican presidential hopeful offered himself to his skeptical right flank Thursday night as a fellow conservative who is passionate about fixing problems and has a record of doing so.

“There are going to be a lot better speakers than me,” Bush told a gathering of the Club for Growth, a conservative advocacy group that has long antagonized the GOP establishment. “That’s great. I’m all for it. If I could get better at it, I’d be all in — trust me.

“But the simple fact is, I got to be governor of this state — this purple state, this wacky, wonderful state — for eight years. I ran as a conservative, I said what I was going to do, and I had a chance to do it. And trust me, I did.”

An establishment favorite, Bush began an aggressive outreach to more suspicious conservatives with an appearance before the group. In 50 minutes of remarks in a speech and question-and-answer session, Bush forcefully defended his positions that have rankled many on the right, including his support for bipartisan immigration reform and for the Common Core set of education standards.

Bush made certain that he has no plan to pander to his party’s conservative base in pursuit of the Republican nomination when he declared, “I’m not backing down from something that is a core belief. Are we all supposed to cower because at the moment people are upset about something? No way, no how.”

The annual Conservative Political Action Conference is at the National Harbor, as conservative students and activists hear from 2016 hopefuls. Here’s a behind-the-scenes look at the sights and sounds of CPAC 2015. (Julie Percha/The Washington Post)

Bush’s pledge will be tested, though, as he wades into the proverbial lion’s den Friday when he speaks at the Conservative Political Action Conference, an annual speechmaking festival that draws thousands of conservative activists to National Harbor outside of Washington.

After two bustling months spent shoring up his natural areas of strength — raising a mountain of cash from the GOP’s monied class, recruiting seasoned policy experts and political operatives, and charming old-guard opinion-makers — Bush is stepping into a new and potentially more perilous phase of his expected candidacy.

The timing is critical for Bush, 62, whose all-but-certain candidacy has attracted legions of financiers and supporters this winter. Despite his fast start, Bush is not outpacing the rest of the GOP field in early polls. Some likely rivals — particularly Wisconsin Gov. Scott Walker — are gaining traction among conservative activists as they begin to travel ahead of next year’s primaries and caucuses.

Bush is trying to reassure doubting conservatives that they can be comfortable with him as their standard-bearer — and that he will not disappoint them on issues like many past presidents and nominees, including his brother, former president George W. Bush, and his father, former president George H.W. Bush.

Central to his argument is his record as governor of Florida. On Thursday, he ticked through what he characterized as his conservative reform accomplishments. He said the state government got smaller and taxes were cut. He said he vetoed so many bills, “they called me Veto Corleone.” He also said he eliminated affirmative action in college admissions at state universities.

Minorities, he said, “don’t need to have a lower standard to get into a university. They need to have higher achievement to be able to go to universities.”

Bush was addressing a few hundred wealthy, fiscally conservative ideologues gathered for the group’s winter meeting over dinner at The Breakers, the venerable luxury resort in Palm Beach.

This year marks the sixth CPAC for William Temple, a tea party activist from Georgia. Dressed in 1770s German and Scottish war garb and waving a giant “Don’t Tread on Me” flag, Temple discusses his plans to lead a walk-out during former Gov. Jeb Bush’s speech on Friday. (Julie Percha/The Washington Post)

In the ornamental Mediterranean Ballroom, underneath a stunning ceiling fresco that evokes Michelangelo’s Sistine Chapel, Bush also delivered his now-familiar “right to rise” message of economic opportunity and creating a better path for working Americans to pull themselves out of poverty.

The Club for Growth focuses its advocacy on lowering taxes and shrinking government, and Bush elicited several rounds of polite, if not enthusiastic, applause when he talked about reforming the tax code and loosening federal regulations.

Bush said that he was open to a flat tax and that his eventual policy plan would be “bigger and broader tax relief.” He called for a wholesale review of how the government regulates, saying the United States had transitioned from the most dynamic to “one of the most complicated countries in the world.”

He also had a message for his party: Conservatives have failed by looking inward and not advancing their cause more broadly.

“We can’t just be against things all the time,” he said. “We have to be for positive, conservative reforms. We should be the reform party. We shouldn’t be the reactionary party to how bad things are. My head explodes every time I watch the news.”

The last time Bush spoke at CPAC, in 2013, he delivered a similar message, which many viewed as an unwelcome lecture.

On Friday, Bush will have a chance to make a new impression before CPAC activists. He is forgoing a traditional speech and instead will field questions in a 20-minute session moderated by Fox News personality Sean Hannity.

Perhaps anticipating a less-than-hospitable reception, Bush associates are organizing to fill the crowd with familiar faces by helping transport longtime Bush family loyalists from downtown Washington to the convention hall at National Harbor, according to organizing details provided in e-mails obtained by The Washington Post.

Other CPAC attendees are organizing a show of force of their own to embarrass Bush. William Temple, 64, a tea party activist from Georgia, said he plans to lead a demonstration against Bush by waving a yellow Gadsden flag — the “Don’t Tread on Me” tea party banner — and calling on conservatives to walk out during Bush’s speech.

“We’re going to stand up, turn around, kick the dust off my feet, raise my flag, and walk out,” said Temple, who is well known for attending national conservative meetings in Revolution-era garb. “We’re going to have several hundred people. I don’t know how many more.”

Matthew A. Schlapp, the chairman of the American Conservative Union, which hosts CPAC, said he was unaware of plans to walk out on Bush.

“I think most people in this audience appreciate the tier-one candidates here,” Schlapp said. “This is also a democratic process, and these people have a right to express their views in any way they can.”

Rather than mingling with friendly donors at receptions, as Bush has done for the past couple of months, he will be asked Friday to address students and conservative hard-liners who have been known to boo speakers associated with the Republican Party’s elite.

“You give him credit for facing his critics and getting out of the bubble of fundraisers and policy speeches,” said Kellyanne Conway, who is managing CPAC’s straw poll. “I don’t think he’s necessarily entering hostile territory, but it’s a less natural habitat for him.”

Bush allies say he has a dual mission: gently walking the party’s base through his conservative views, and sparking a connection by speaking vividly about his record in Florida on social and economic issues.

“This is the first time Jeb’s at CPAC as a potential national candidate. He hasn’t been in elected office in almost 10 years. He needs to reintroduce himself to the conservative base,” Bush confidant Ana Navarro wrote in an e-mail. “Many of them are not familiar with or have forgotten his record. He needs to offer a refresher course.”

Costa reported from Washington.