John McCainJohn McCainMcCain calls North Korean leader a 'crazy, fat kid' McCain: Congress doesn't have 'credibility' to handle Russia probes Dem senator: House Intel chairman may have revealed classified info 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.

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