CHEYENNE, Wyo. – Before he became a U.S. senator, Mike Enzi ran a shoe store and was mayor of Gillette, in the heart of Wyoming’s coal country.

Making payroll as a small businessman and sticking to a budget as a local government official drives Enzi now as he leads a bipartisan group of senators pushing legislation to help states recover billions in sales taxes they’re losing to Internet sales.

“We need to fix this so that the loophole doesn’t exist anymore, and that will take care of those local governments without the federal government having to raise more taxes for them,” Wyoming’s senior Republican senator said this week.

Under the Marketplace Fairness Act, the 45 states with state sales taxes could require online retailers that sell more than $500,000 a year to collect sales taxes for them regardless of where those retailers are headquartered. Internet retailers currently must collect sales tax only for those states they have a presence in, such as a store or an office.

In some cases, online consumers are required to pay tax to their home state but don’t always do so. States striving to make ends meet in tough times will lose more than $23 billion in uncollected sales taxes in 2012, the National Conference of State Legislatures estimates.

“I used to be a retailer, and I find it discouraging when somebody comes in and they pick something up and they say, ‘Now if you’ll sell it to me without the sales tax, I’ll buy it,’ ” Enzi said.

“And you say, ‘Well that would be illegal, I can’t do that.’ And they come up with some alternate plans for how you could ship it out of state for them. But if you’re a brick-and-mortar business, if you actually live in the community, then that’s not an option. So they go and they buy it online so they don’t have to pay sales tax.”

Enzi said he commonly hears from Wyoming retailers that addressing the tax issue is essential for main street businesses that provide jobs and help their communities. Under the bill, state governments would share tax revenues with local governments based on address records of people ordering goods online.

Enzi and Sens. Dick Durbin, D-Ill., and Lamar Alexander, R-Tenn., lead the group of 10 U.S. senators behind the bill.

Internet retailer Inc. has said it supports the bill. The company fought taxation efforts in several states but said it would prefer a federal solution.

Online auction company eBay Inc. opposes the legislation, saying it would place an unfair burden on small retailers to collect and remit sales taxes around the country. Enzi said he believes that exempting businesses with less than $500,000 in sales addresses those worries.

Enzi doesn’t accept the argument from some Internet companies that they shouldn’t have to collect taxes for states in which they don’t have a physical presence or use state services. Nor does he accept the argument that states should simply learn to live with less.

“Live with less, so that out-of-state retailers can live with more?” he asked. “No, I don’t think that’s a legitimate one to ask your out-of-state businesses to put your in-state businesses out of business.”