CQPolitics: Sens. John Kerry and Joseph I. Lieberman will unveil a long-awaited climate change bill on May 12, without the participation of their former partner, Sen. Lindsey Graham, who had been the measure’s only Republican supporter. Graham bolted from the climate talks two days before the originally scheduled April 26 bill rollout over anger at reports that Majority Leader Harry Reid planned to bring immigration legislation to the Senate floor ahead of the climate bill. Graham, who …