"Sen. John McCain once led the global warming debate on Capitol Hill, pledging to force repeated floor votes on cap-and-trade legislation until it passed.

"Over time we will not be elected Miss Congeniality in the Senate, but we will win," the Arizona Republican said in April 2006.

But McCain has gone on hiatus from the issue since losing the presidential election to Barack Obama. And he is likely to keep his distance even more over the next six months due to a primary challenge from a conservative former congressman that threatens to end his Senate career after four terms."

Darren Samuelsohn reports for ClimateWire February 10, 2010. [2]