Setting aside personality clashes for a night, the Republican Party's 2016 contest shifted to substance Friday as a slate of White House hopefuls vowed to steer the nation sharply to the right as they courted conservatives in battleground South Carolina.

They promised to eliminate federal departments that regulate education and environmental protection, called on congressional leaders to block federal funding from Planned Parenthood even if it triggers a government shutdown, and endorsed policies that reduce the number of unwed mothers.

"Just once, Republicans should nominate someone who is as committed to conservative principles as Barack Obama is committed to liberal principles," Texas Sen. Ted Cruz told a crowd of thousands gathered in a South Carolina arena.

Ten candidates were featured at the event just two days after the GOP's 2016 class met for its second debate, a California faceoff that exposed deep rifts between the candidates on immigration, foreign policy and the Supreme Court's ruling on same-sex marriage. Yet the debate, like much of the early 2016 primary season, devolved at many times to a battle of personalities — with brash billionaire Donald Trump the leading antagonist.

Trump was a late scratch for Friday's presidential forum, hosted by Heritage Action for America, the political arm of a Washington-based conservative think.

Even among a friendly crowd, there were tense moments.

Former Florida Gov. Jeb Bush triggered boos when he defended his early support for the Common Core education standards, a policy developed by state leaders in both parties that has become a target of tea party ire.

"I'm for higher standards, and Common Core standards are higher than the standards that exist," Bush said before being interrupted by boos. "If South Carolina wants to be without Common Core standards, great, just make sure the standards that you apply are higher than the ones before you had Common Core. Standards matter. Accountability matters."

Wisconsin Gov. Scott Walker, who previously supported Common Core himself, promised that he'd "take all the education money out of Washington" and send it to individual states. In addition to closing the federal education department, he called for the same shifts in federal funding for transportation, the environment, workforce development and Medicaid, the health-care program for the poor.

Walker also called for congressional Republicans to strip federal funding from Planned Parenthood even if it causes a government shutdown. He suggested that Senate Republicans use the so-called "nuclear option" to bypass filibuster rules that often require 60 votes to proceed on contentious issues.

"We don't have to play by those rules," Walker said.

The event also featured retired neurosurgeon Ben Carson, Florida Sen. Marco Rubio, former technology executive Carly Fiorina, New Jersey Gov. Chris Christie, Kentucky Sen. Rand Paul, former Pennsylvania Sen. Rick Santorum and Louisiana Gov. Bobby Jindal.

Immigration emerged as a focus for many candidates, who took turns answering questions on the main stage for roughly 20 minutes each.

Rubio, who supports a pathway to citizenship for immigrants in the country illegally, criticized the government's tracking system for immigrants who come legally and then overstay visas: "America has become a hotel that checks you in and never checks you out."

Carson cited his recent proposal for a guest worker program for such immigrants to perform "work that Americans won't do." He mentioned agricultural workers.

But he avoided a question about whether those workers would have permanent legal status and be eligible for various federal benefits. "Guest workers are not eligible for anything unless we, the American people, decide" they are, he said.

Santorum, who wants to reduce legal immigration, railed against President Barack Obama's call to bring at least 10,000 Syrian refugees to the U.S. He said that previously resettled Syrian immigrants were all Muslims and offered a direct message to the president about the incoming refugees.

"You tell us what the breakdown is of religions," Santorum declared. "There are a lot of religions that are being persecuted in Syria, and they should have a home here in the United States just like everybody else."

The event was awash in fiery rhetoric, but no candidate has struggled more with his party's conservative base than Bush.

"He could perform like Superman in the debates, but he's dead in the water with the tea party and the base generally," said tea party movement co-founder Mark Meckler. "He's the only candidate they absolutely loathe."

South Carolina's Feb. 20 primary shapes up as a critical bridge between the traditional opening states of Iowa and New Hampshire and a March 1 "Super Tuesday" that features a gaggle of Southern states, from Virginia to Texas.

Notably absent from Friday's affair was the state's senior senator and presidential hopeful Lindsey Graham, who finds himself languishing at the bottom of the polls nationally.

Graham is a strong figure politically in South Carolina, but the most conservative activists in the Republican Party view him as too moderate and too willing to negotiate with Democrats.