Republican Presidential candidate Donald Trump waves following a speech on board the World War II bettlaship USS Iowa in San Pedro, California on September 15, 2015
Simi Valley (United States) (AFP) - Free from having to square off against irreverent Republican frontrunner Donald Trump in person, four low-polling candidates took the debate stage Wednesday and slammed the billionaire as a non-Republican unfit to be president.
Fireworks were expected in the main event to follow, where Trump takes center stage with 10 challengers in the crowded 2016 nomination battle, as rivals build their case against the real estate tycoon and his claim that he is the best person to take on Democratic frontrunner Hillary Clinton.
But they kicked off early, with three of the four men on stage, decades of public service between them, hitting Trump for his lack of political experience.
"Let's stop treating Donald Trump like a Republican," said Louisiana Governor Bobby Jindal, referring to the left-leaning positions on issues such as abortion and taxes that Trump has previously held.
"If he were really a conservative and 30 points ahead, I would endorse him."
Trump has thoroughly upended the Republican race, soaring to the top of opinion polls and leaving establishment candidates like former Florida governor Jeb Bush in their wake. The four low-polling candidates in the early debate basically were on life support.
Candidates who fared poorly in the event are under threat of becoming the next casualty in the crowded race for the Republican nomination, after Rick Perry dropped out last week.
But as debaters prepared to lay out their policy prescriptions and discuss key issues from immigration and taxes to the Syrian refugee crisis and radical Islam, the CNN-hosted debate's first four questions were about Trump, leading former New York governor George Pataki to show a flash of frustration.
"Donald Trump is unfit to be president of the United States," Pataki said.
Senator Lindsey Graham also warned against repeating the mistake of hiring an inexperienced commander-in-chief like Barack Obama, who was a one-term senator before winning the White House.
"I hope you believe that experience matters," Graham said, citing his former military service and his years of engagement in the Middle East. "Let's not replace one novice with another."
Former senator Rick Santorum, who finished second in the 2012 nomination race, sought to steer the discussion away from Trump, saying "personal attacks please just one person: Hillary Clinton."
The junior varsity debate has most of the same candidates as last month, with a notable exception.
Carly Fiorina, the former Hewlett-Packard chief executive, was bumped up to the main stage for Wednesday night, following her breakout performance in the previous undercard.