DES MOINES, Iowa - It's an overriding conservative principle: Scale back government interference and let businesses survive or fail on their merits.

But standing by that principle may hurt Mitt Romney in Iowa, a hotly contested swing state that could provide a crucial six electoral college votes in November.

Romney recently upset many conservatives here by saying he would end a government tax credit that helps subsidize a burgeoning wind industry in the state. Some of them - farmers who earn tens of thousands of dollars a year for having wind turbines on their property - say they won't vote for Romney because of his wind position. Others, including Rob Hach, a lifelong Republican who owns a wind-energy business, even say they'll now vote for President Obama.

"It's critical for the economy," said Hach, whose company, Anemometry, moved into a shuttered furniture store in rural Alta and then expanded to an abandoned lumberyard. "Right now, the Midwest is experiencing an intense drought, and the wind turbines are producing revenue for farmers, while the crops are not."

It is not just rural voters in Iowa who are invested in wind. Throughout the Midwest, wind turbines are popping up in areas once sustained by agriculture or manufacturing. The industry has created 7,000 jobs in Iowa, opening manufacturing plants in towns where Maytag factories once operated. Wind creates 5,000 direct and indirect jobs in Ohio, the fastest-growing state for new wind-power installations last year, and 1,000 jobs in Indiana, according to the American Wind Energy Association, a trade group.

Conservatives such as Hach say they don't want handouts. But in the heartland, where the population has declined as younger generations have moved to the cities, the idea of an industry that could resuscitate struggling towns is an exciting one.

"Iowa is known for brain drain, when talented farm kids leave the state," Hach said. "But wind turbines could help bring them back."

Many Republicans in Congress support tax credits for renewable energy, including Iowa Sen. Charles E. Grassley, South Dakota Sen. John Thune and Iowa Rep. Tom Latham, who introduced Romney at an event Wednesday in Des Moines (though when a Latham aide was asked about the tax credits before the event, she covered her ears with her hands, said "I can't hear you," and walked away).

At issue is a production tax credit, set to expire this year, that allows wind farms to receive a credit of 2.2 cents per kilowatt-hour of electricity they produce. It has not been allowed to expire since it was signed into law in 2005, but last week, a Romney spokesman told the Des Moines Register that Romney "will allow the wind credit to expire, end the stimulus boondoggles and create a level playing field on which all sources of energy can compete on their merits."

The comment irked Iowa's Republican Gov. Terry Branstad and many in the state's Republican congressional delegation. Branstad called Romney's staffers a "bunch of East Coast people that need to get out here in the real world to find out what's really going on," in an interview with Radio Iowa last week.

He slightly tempered his criticisms this week.

"I can understand why he objects to Solyndra and all the boondoggles Obama has supported with the stimulus, but remember, the wind energy tax credit [was proposed] by Sen. Grassley and way preceded Obama," Branstad said in an interview. "It's a tool that's helped us grow this energy. . . . We love it."