Sens. John F. Kerry (D-Mass.) and Joseph I. Lieberman (I-Conn.) unveiled a compromise climate bill Wednesday, hoping public concern over the massive oil spill in the gulf will boost the measure's long-shot chances for passage. While the bill is different from the House-passed climate bill in several respects -- it seeks carbon reductions from separate sectors of the economy rather than imposing a nationwide cap, and it provides more incentives for both new nuclear power and offshore oil drilling -- it still faces a steep hill in attracting the 60 votes needed for passage. Senate Majority Leader Harry Reid (D-Nev.)...