Silence, pushback from governors on letter by top Senate Republican urging defiance of EPA

The top Senate Republican's call for governors to defy proposed federal rules to limit pollution has been met with mostly silence, but leaders in downwind New England states and drought-stricken areas in the West are pushing back.

Senate Majority Leader Mitch McConnell wrote to governors in March after the Environmental Protection Agency proposed a rule to limit carbon pollution from existing coal-fired power plants. The Kentucky Republican said he thinks the rule is illegal and will hurt the economy.

Democratic Vermont Gov. Peter Shumlin wrote to McConnell and backed the EPA, saying climate change is real. "It's a threat to humanity," he wrote.

In bone-dry California, Democratic Gov. Jerry Brown called McConnell's effort "immoral."

Republican Wisconsin Gov. Scott Walker said he opposes the EPA rule and his state is challenging it.