GOP presidential hopefuls shift on global warming

GOP presidential hopefuls shift on global warming: "WASHINGTON (AP) -- For Republican presidential contenders who once supported combatting global warming, the race is heating up. Faced with an activist right wing that questions the science linking pollution to changes in the Earth's climate and also disdains big government, most of the GOP contenders have stepped back from their previous positions on global warming. Some have apologized outright for past support of proposals to reduce heat-trapping pollution. And those who haven't fully..."