OKLAHOMA CITY — A year after Republicans swept into office across the country, many have trained their sights on what has long been a fiscal conservative’s dream: the steep reduction or even outright elimination of state income taxes.

The idea has circulated among academics and think-tank researchers for years. But it’s moving quietly into mainstream political discourse, despite the fact that such sweeping changes would almost certainly mean a total rewiring of tax systems at a time when most states are still struggling in the aftermath of the recession.

“I think there’s going to be more action that way,” especially as Republican governors release their budget plans, said Kim Rueben, an expert on state taxation at the Brookings Urban Tax Policy Center.

Last year, GOP lawmakers in many states quickly went to work on a new conservative agenda: restricting abortion, cracking down on illegal immigration, expanding gun rights and taking aim at public-employee unions.

Emboldened by that success, the party has launched income tax efforts in Idaho, Kansas, Maine, Missouri, Ohio, Oklahoma and South Carolina. But it’s not clear how all those states would make up for the lost revenue, and Rueben said she’s not aware of any state in modern history that has eliminated an income tax.

Nine states already get by without an income tax, mostly by tapping other sources of revenue. Nevada and Florida rely on sales taxes that target the tourism industry.

Alaska has taxes on natural resources, and Texas imposes substantial property taxes.

The other five states are: New Hampshire, South Dakota, Tennessee, Washington and Wyoming.

But in the rest of the country, income taxes pay for bedrock government services, including roads and bridges and schools and prison systems.

In Oklahoma, Republican Gov. Mary Fallin says gradually cutting the top income-tax rate of 5.25 percent will make the state more attractive to businesses, help spur economic growth and ensure Oklahoma is competitive against neighboring states such as Texas.

South Carolina Gov. Nikki Haley is pushing this year to consolidate four personal income tax brackets and to phase out corporate income taxes.

And Maine’s GOP-controlled Legislature voted last year to lower the income tax from 8.5 to 7.95 percent, taking 70,000 low-income citizens off the income-tax rolls.

As one way to compensate for the lost revenue, the Oklahoma governor and others have suggested eliminating other kinds of tax breaks and incentives, specifically transferrable tax credits offered to certain businesses.

But that would still fall woefully short in Oklahoma, where the income tax provides more than one-third of all state spending.

Still, 23 Republicans in the Oklahoma House have signed up as sponsors of a measure to abolish the income tax over the next decade without raising any other taxes.

Lower taxes appeal to many voters, but some wonder how the state could get by if lawmakers abandon a major source of money.

“I personally would favor paying less taxes, but to me, it’s like where are we going to make up the difference?” said Steve Schlegel, a bicycle shop owner in Oklahoma City. “I already feel like government is underfunded at the moment.”

Conservatives say the lost revenue will be made up by increased economic activity – more businesses paying corporate taxes and more employees paying property taxes and spending money. But economists warn those predictions are unrealistic.

Without creating an alternative funding system, “it’s clearly irresponsible to propose taking action against the income tax,” said Alan Viard, an economist with the American Enterprise Institute, a Washington, D.C.-based conservative think tank.