Trump tangles with Republican opponents in 2nd U.S. debate

Republican presidential candidate Donald Trump speaks during a campaign event aboard the USS Iowa battleship in Los Angeles on Sept. 15, 2015. (AP / Kevork Djansezian)

SIMI VALLY, Calif. -- Donald Trump came ready to take on any opponent on the crowded stage in the second Republican debate Wednesday night, firing off in all directions from the start as other candidates tried to puncture his high-flying candidacy.

The front-running billionaire businessman and brash front-runner has so far proven untouchable despite a series of remarks that would have undone a more traditional candidate. And he's been unpredictable, as he was in the first moments of the debate: unprompted, he declared that fellow 2016 presidential candidate Rand Paul shouldn't even be on the stage.

Standing at centre stage, Trump declared that he had a "phenomenal temperament" and a record in business that would help him on the world stage.

Former Hewlett-Packard CEO Carly Fiorina, the only woman in the Republican field, drew big applause when asked about Trump's earlier denigration of her appearance, about which he later backtracked.

"I think women all over this country heard very clearly what Mr. Trump said," Fiorina said as Trump's face became red.

Trump retorted: "She's got a beautiful face, and she's a beautiful woman."

The unlikely rise and surprising staying power of Trump, who remains a longshot for the White House and has never held public office, has sidelined all other candidates. Trump is no longer dismissed as a summer fling for frustrated voters, and is increasingly seen as a candidate who could remain atop the field for months and win some early state primaries.

Trump surprise climb to the top of the field has unnerved Republican leaders who fear the former reality TV star's tough talk, especially about women and Hispanic immigrants, is damaging the party's brand and imperiling its chances of winning back the White House after President Barack Obama's eight-year tenure is over. Trump has so far been immune to criticism for his lack of specific policy proposals, his incendiary rhetoric and his uneven support of conservative principles.

The first question of the debate went to Fiorina, who called Trump a "wonderful entertainer" but said all the candidates' characters would be revealed over time and under pressure.

Paul, the only candidate to directly challenge Trump in the first debate, said he's worried about having Trump in control of the U.S. nuclear arsenal, citing his "careless language" and attack on people's appearances.

"Do we want someone with that kind of character, that kind of language to be negotiating with (Russian President Vladimir) Putin?" Paul said.

There was plenty of back and forth between Trump and Bush, the brother and son of presidents who had been expected to be a favourite in the race and has now become the real estate mogul's top target.

Bush tried to take on Trump directly in the debate's early moments but was repeatedly interrupted by the Republican front-runner. As Bush tried to finish an answer, Trump chimed in: "More energy tonight, I like that."

Trump's jab was a reference to his frequent critique that Bush is a "low energy" candidate.

Fiorina was the newest addition to the main debate after a standout performance in an undercard event last month. The race has seen another unlikely surge, as soft-spoken retired neurosurgeon Ben Carson has leapt into second place, according to polls.

As Fiorina argued with Trump about who had a better business record, New Jersey Gov. Chris Christie broke in to say that Americans really wanted to know what a Republican president would do to improve their lives.

"You're both successful people. Congratulations," Christie said." The middle class in this country who's getting plowed under by Barack Obama and Hillary Clinton, let's start talking about those issues tonight and stop this childish back-and-forth between the two of you."

Both Bush and Walker took early swipes at Trump. Bush said Trump made donations to him the past because he wanted casino gambling approved in Florida when Bush was governor. Trump denied that.

Bush has become one of Trump's favourite targets. Generally a low-key, policy-focused candidate, Bush has grown visibility irritated by Trump's jabs.

Bush said Trump needed to apologize for bringing his wife into a political debate. Bush's wife is an American citizen born in Mexico, and Trump has suggested Bush is too soft toward immigrants because of his marriage.

Trump refused to apologize, said his words have been misconstrued and stood by his criticism of Bush for answering some questions from reporters in Spanish. He said people in the United States should speak English.

Bush said he shows respect to people who speak both languages. Florida Sen. Marco Rubio jumped in and said it's important to speak Spanish to communicate with immigrants who may become Republican voters. He recounted stories of his grandfather, a Cuban immigrant whose English was shaky but who idolized Ronald Reagan.

Four candidates lagging behind in national polls did not qualify for the main event and were relegated to an earlier debate: Louisiana Gov. Bobby Jindal, South Carolina Sen. Lindsey Graham, former Pennsylvania Sen. Rick Santorum and former New York Gov. George Pataki.

Associated Press writers Steven R. Hurst, Julie Pace, Steve Peoples, Thomas Beaumont and Scott Bauer contributed to this report.