Taxing a repugnant transaction?

Nevada's legal brothels are asking to be taxed by the state, as a hedge against a change in sentiment that might make prostitution illegal once more in Nevada, as it is in other states: Brothels Ask to Be Taxed, but Official Sees a Catch

"The industry’s lobbyist, George Flint, director of the Nevada Brothel Association, has been approaching the Legislature’s leadership for months about creating an entertainment tax that would require the state’s 25 legal brothels to give the state some money on a per-transaction basis. ..."
"Nevada is the only state where prostitution is legal, but by state law it also is restricted to counties with fewer than 400,000 residents. That outlaws it in two counties, Clark, which contains Las Vegas, and Washoe, which contains Reno. There are about 225 women licensed by the state as prostitutes; no county allows brothels to have men who sell sexual services." (emphasis added; I guess some repugnancies are stronger than others)
"Still, since 1971, when prostitution was legalized, Nevada has added more than two million residents and become significantly more socially conservative. The state has also lost much of its frontier mentality, so Mr. Flint acknowledges that the tax effort is “something of an insurance policy” against the Legislature’s deciding one day to do away with the industry.
“Anytime you’re going to take tax money, the state’s not going to view you as a relic of a past time and put you out of business,” explained Mr. Flint, who said he was gaining traction for a brothel tax in 2003 until he made the faux pas of joking to a reporter that he would commit to putting the governor’s portrait in every prostitute’s lair along with a note reading, “Don’t forget the governor’s share.” "