SUMMARY: The Philly debate brought a new controversy into the campaign: Obama's ties to a former member of the Weather Underground. We check the facts.

Sens. Hillary Clinton and Barack Obama were just a few blocks from Independence Hall, but their debate on April 16, 2008 had few fireworks. It did, however, raise a new controversy that had already been simmering on conservative blogs: Obama's ties to a former member of the Weather Underground.

Clinton spent much of the debate suggesting that Obama's background had not been fully explored. Obama said voters were tired of campaign sniping that distracted from critical issues.

We checked several facts from the debate:

• Clinton correctly characterized the relationship between Obama and William Ayers, a former member of the Weather Underground, earning another True.

• Obama accurately described income inequality, saying it was the largest gap since the 1920s. We rated that True.

• Clinton was right that Iranian leader Mahmoud Ahmadinejad has recently said he has doubts about what the U.S. says happened in the Sept. 11 attacks. We rated that one True.