Could a rising political backlash over fracking portend big headaches for Hillary Clinton and her likely 2016 presidential bid? Environmentalists are traditional allies of the Democrats. But Clinton and other party leaders who support hydraulic fracturing of shale rock -- and the energy boom it has produced -- are now in the green movement's cross hairs.

When Clinton gave a speech in October lauding the nation's oil and gas boom, she was condemned by New Yorkers Against Fracking for her "backward, 20th-century belief" that fossil fuel extraction is good for America. In Colorado, Democratic governor John Hickenlooper supports fracking but has tried to contain a growing local backlash with robust regulation of natural-gas drilling. His reward: Voters in four towns rebelled this fall, passing bans or moratoriums. Colorado is now in the awkward position of suing a fifth town, Longmont, which passed the state's first ban last year, in order to protect the state's legal authority. Its litigation partner: the oil and gas industry.

Environmental concerns -- particularly the potential for groundwater contamination -- are fueling the antifracking movement nationally, despite industry efforts to demonstrate that the process is safe. But in Colorado there's also a not-in-my-backyard factor: Fracking has given rise to industrial developments tucked beside homes and schools and family farms. No one wants his family's neighborhood to be "fracked."

Most governors have embraced the revolutionary potential of hydraulic fracturing. They like the sound of fracking: 1.7 million jobs and rising, billions in revenue flowing into state coffers, revived manufacturing sectors, and, of course, cheaper and (in the case of natural gas) cleaner sources of energy. Governors who are on the fence about fracking, like New York's Andrew Cuomo, who keeps ordering more studies on the practice, face the wrath of the left and the right alike.

Other Democrats feeling the heat of a smoldering antifracking movement include President Obama, whose EPA is under attack for failing to hew to activist doctrine that fracking poses a danger to public health and safety. The EPA, which previously concluded the methane contamination was naturally occurring.

The big unknown is domestic politics. Industry leaders mostly dismissed last fall's Colorado votes as symbolic. That sounds like wishful -- and shortsighted -- thinking. Signs of public alarm will be picked up and broadcast by nervous politicians. Starting with the 2016 Democratic presidential candidates.

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