The latest issue of Bloomberg Businessweek profiles a Tampa lawyer who’s developed a new method for taking on labor unions.

Last year, the Democrats who control the Kentucky House of Representatives killed a Republican proposal that would have made it illegal for unions to charge workers at private companies mandatory fees—in other words, to run union shops. One of the bill’s sponsors, Representative Jim DeCesare, assumed his option was to try again in the next General Assembly session. Then, at an October fundraiser for Senator Rand Paul in Bowling Green, DeCesare heard about a Tampa lawyer named Brent Yessin. He argues that counties and cities have the right to make labor policy, too. “Obviously,” DeCesare says, “we were extremely interested.”

In 1965, Kentucky’s highest court ruled that the town of Shelbyville couldn’t outlaw union shop contracts because the 1935 National Labor Relations Act preempts local labor laws. In 1990 a similar law passed by a New Mexico city was overturned by a federal district court for much the same reason. Letting local governments diverge on labor policy, says University of Toledo law professor Joseph Slater, “would certainly be a change in the way the law has always been interpreted.”

Yessin, who’s represented companies in more than 200 conflicts with unions, says those interpretations have been wrong all along. In his view, the NLRA—which was intended to standardize labor laws across the country—doesn’t block states from letting local officials regulate some union activities. Even if it did, he argues, Congress doesn’t have the power to take that authority away from cities and counties. “States never lost the ability to pass their own regulatory schemes regarding forced union dues,” he says. “It’s not up to Congress to tell them how to utilize it.”

Perhaps Yessin’s work will contribute to the decline in labor union membership.