John McCainJohn McCainGraham: Free press and independent judiciary are worth fighting for Drug importation from other countries will save dollars and lives Rand Paul: We’re very lucky John McCain’s not in charge MORE's stance on climate change has proven to be controversial with at least one group of economic conservatives, as the Club for Growth today criticized the Arizona Republican's support for a cap-and-trade system.

The concept would set mandatory limits on greenhouse emissions, and allow companies that pollute less to sell their permits to those that pollute more.