Senators John Kerry and Joe Lieberman have unveiled the American Power Act, their climate bill that aims to curtail global warming-related emissions, reduce oil imports, and create energy-related jobs. The legislation would cut emissions from carbon dioxide and other greenhouse gases by 17 percent by 2020 and by more than 80 percent by 2050. In response to the oil spill in the Gulf of Mexico, the bill was changed recently to allow states to prohibit offshore drilling within 75 miles of their coasts, while provisions were kept to encourage offshore exploration. But the climate bill faces a tough challenge to get passed. Senator Lindsay Graham, the bill's only Republican backer, withdrew his support last week, citing problems created by the Gulf oil spill and a need to focus on immigration reform. What are the chances of climate legislation passing the Senate?