Four GOP candidates took to the stage tonight for a debate in South Carolina hours after Texas Gov. Rick Perry dropped his bid and endorsed former House Speaker Newt Gingrich.

Perry's dropout came just two days before the South Carolina primary. He says he made the decision because there was "no viable path forward" for his campaign.

In the debate tonight, Gingrich was asked about his personal life. ABC is set to air an interview this evening with one of his ex-wives, who said Gingrich asked her if they could have an open marriage so he could continue an affair.

Meanwhile, former Massachusetts Gov. Mitt Romney says he plans to release his tax returns after much prodding from his opponents. And while Romney has been touting his win in the Iowa caucuses, the runner-up in that race, former Pennsylvania Sen. Rick Santorum, claims that a recount shows he actually finished ahead of Romney.

Officials say Romney's lead is fading as South Carolina voters head to the polls on Saturday.

Presidential hopeful Romney makes history in NH