Candidates to watch during the Republican debate
Donald Trump may lead the polls at this early stage in the race, but there are a handful of Republican candidates who could step into the driver's seat if the billionaire contender wipes out.
Real estate mogul
Four months ahead of the first nominating contest for the November 2016 election, Donald Trump still heads the pack. The brash 69-year-old billionaire led the polls of Republican voters at the first debate, making headlines with populist promises and by mocking his rivals. Trump has never held an elected office, and his rants against immigrants and women have already alienated voters.
Creationist neurosurgeon
Ben Carson is the only candidate who has managed to gain significantly on Trump. His support has surged from 6 percent to 23 percent, just four points behind Trump, according to a "New York Times"/CBS poll. The retired neurosurgeon has never held public office, has no political experience and is an evangelical Christian who doubts the validity of evolution.
Saber-rattling senator
Ted Cruz has consistently led the Republican right wing into battle. A staunch opponent of abortion rights, the Texas senator is at the forefront of the current campaign to end public funding for Planned Parenthood. Though he's only registering at around 5 percent in the polls, Cruz has $52.5 million (46.6 mln euros) at his disposal, making him second only to Jeb Bush in Republican fundraising.
Union-busting governor
Scott Walker made his name fighting organized labor. He severely restricted collective bargaining rights for most public sector unions in Wisconsin. The governor was a front-runner earlier in the summer, but his support has collapsed from 10 percent to a meager 2 percent. In an effort to revive his flagging campaign, he has proposed legislation that would eliminate unions at the federal level.
Next-generation conservative
Marco Rubio is a young, bilingual, first-generation American born to Cuban parents. The 44-year-old first-term senator from Florida has the potential to revamp the Republican Party and expand its base of support beyond aging white voters to a more diverse generation of conservatives. Rubio sits at 6 percent in the polls, but he's the third largest fundraiser with $42 million (37.3 mln euros).
Establishment favorite
When Jeb Bush announced his candidacy in June, he was widely viewed as the default Republican front-runner. But the former Florida governor's moderate positions on immigration and education and his restrained personality have failed to mobilize conservative primary voters. Bush remains the well-networked, well financed establishment candidate with a whopping $120 million at his disposal.