With just under three weeks left until the start of the presidential nominating process, the top Republican contenders faced off Thursday in what was expected to be a contentious debate in the influential early primary state of South Carolina.
The candidates began by taking aim at the man they hope to replace: President Barack Obama.
In his opening statement, U.S. Senator Ted Cruz of Texas slammed the president's handling of an incident earlier this week in which 10 U.S. sailors were briefly held by Iran after their boats apparently wandered into Iran's territorial waters in the Persian Gulf.
New Jersey Governor Chris Christie also focused on Obama, promising to "kick [the president's] rear end out of the White House" and referring to him as a "boy" and a "petulant child." Christie also took issue with the president's largely optimistic State of the Union address.
"On Tuesday night I watched storytime with Barack Obama and it sounded like everything was going amazing," Christie said. He also slammed Obama's handling of the sailor incident.
"In a Christie administration, they would know much better than to do that," he added.
Watch video report from VOA's Jim Malone:
Clinton also in GOP sights
Another prominent focus early in the debate was Democratic presidential front-runner Hillary Clinton.
Former Florida Governor Jeb Bush brought up the controversy over Clinton's use of a personal email server during her time as secretary of state, saying it could distract her if she became president.
"If she gets elected, her first 100 days, instead of setting an agenda, she might be going back and forth between the White House and the courthouse," Bush said, to applause.
Taking center stage at the nationally televised debate was billionaire real estate mogul Donald Trump, who continues to lead in almost all national polls.
Trump defended his tough proposals on border security, which some have said are discriminatory against Mexicans and Muslims.
"We can't let all these people come into our country and break our borders. We can't do it," Trump said.
Some polls show Cruz leading Trump in the rural state of Iowa, where party members will vote at caucuses on February 1, kicking off the months-long series of state-by-state contests leading to the party's national convention in July to pick a nominee.
Trump and Cruz, who both appeal to nontraditional voters upset at the GOP establishment, have in recent days traded a series of increasingly sharp attacks, and that pattern continued at Thursday's debate.
On the campaign trail, Trump has repeatedly brought up the issue of whether Cruz is qualified under the constitution to become president, since he was born to a Cuban father and an American mother in Canada.
Addressing the controversy, Cruz accused Trump of political opportunism in bringing up the issue. "The Constitution hasn't changed since September, but the poll numbers have," he said.
Cruz instead said the focus should be on "important" issues. "I suggest we focus on who is better qualified to be commander in chief, because that's what matters."
In response, the blunt-speaking Trump acknowledged that he was raising the issue because "because now [Cruz] is doing a little better." He also quoted experts who say there is a "serious question" about whether Cruz meets the constitutional requirement of being a "natural born citizen."
"There's a big question mark over your head, and you can't do that to the party," Trump said. "Who the hell knows if you can even serve in office?"
The frequent clashes between Cruz and Trump were one of the main themes of the debate.
In one particularly feisty exchange, Cruz repeated his recent accusation that Trump has "New York values," observing that "not a lot of conservatives come out of Manhattan."
Trump hit back, saying New York has "great people" who "beautifully" handled the aftermath of the September 11, 2001, terror attacks. "That's a very insulting statement that Ted just made," Trump said.
Cruz loan controversy
Cruz also addressed the controversy over a recent New York Times article that claimed the senator failed to disclose, as required, a 2012 Senate campaign loan.
As he has in past debates, Cruz lashed out at the news media, calling the article a "hit piece" and saying that "if that's the best hit The New York Times has got, they better go back to the well."
However, Cruz also acknowledged some fault for not reporting the loan from Goldman Sachs. "I made a paperwork error," he said.
The debate also included Ohio Governor John Kasich, retired neurosurgeon Ben Carson and U.S. Senator Marco Rubio of Florida.
Rubio: Obama would take all guns
Rubio hit at Obama on gun control, slamming the president's recent executive actions aimed at reducing gun violence as inappropriate and ineffective. He also suggested Obama does not want any Americans to have guns.
"I am convinced that if this president could confiscate every gun in America, he would. I am convinced that if he could get rid of the second amendment, he would," Rubio said, referring to the part of the Constitution which protects the right to bear arms.
Instead of focusing on restricting guns, Rubio said his future administration would deal with eradicating terrorist groups, including the Islamic State. Obama "consistently underestimates" IS, Rubio added.
Rubio also launched a volley of attacks at Cruz for allegedly changing positions on several key issues involving immigration.
"That is not consistent conservatism, that is political calculation," said Rubio.
"I appreciate you dumping your oppo research there," said Cruz.
"It's your record!" Rubio responded.
The two Cuban-American senators are locked in a tight battle for second place behind Trump.
The debate also included Ohio Governor John Kasich and retired neurosurgeon Ben Carson.