Remember that corny old Kenny Rogers tune about "when to hold 'em, when to fold 'em, and when to walk away"? Somebody should have played that song for Fort Bend County Sheriff Troy Nehls last week, before he launched a pointless crusade against a local resident over a bumper sticker he didn't like.

Karen Fonseca and her husband advertise their disapproval of the current president with a custom-made sticker on the back window of their pickup that pointedly reads "F--- Trump and f--- you for voting for him." Rude? Yes. Profane? Check.

Illegal? No, and you don't have to be a law scholar to know it. Yet Nehls, who claimed he was acting on vaguely specified "citizen complaints," posted a photo of the truck on his Facebook page, asking for information about who owned it -- and issuing a not-very-veiled threat that the driver might face arrest on charges of disorderly conduct.

Met with a swift outcry that the sticker, while clearly distasteful, does not violate the law, Nehls' department instead arrested and jailed Fonseca on an unrelated charge: a months-old outstanding warrant from another county, reportedly for using a false form of identification two years ago.

Nehls claimed his department "received information" about the outstanding warrant "as a result of the publicity" -- publicity which his own department generated through his ill-advised Facebook post. The explanation did little to dispel the appearance, at least, that the sheriff purposely targeted the 46-year-old mother of 12 over political differences and a tacky bumper sticker.

Maybe he should have started and ended this effort by consulting his own district attorney before the standoff blew up into a social media sensation du jour. "The elements of the crime of disorderly conduct are not met," Fort Bend County District Attorney John Healey told the The Washington Post. "No matter how distasteful it may be, it should not be prosecuted."

On Monday, State Rep. Ron Reynolds, D-Missouri City, waded into the fray, demanding that Nelms issue a formal apology to Fonseca.

"A difference in political views does not give Sheriff Nehls the right to target citizens," Reynolds said during a press conference held Monday outside the sheriff's office. "These actions by Sheriff Nehls could be an abuse of his law enforcement authority."

For his part, Nelms has abruptly clammed up, saying he will have nothing further to say due to "hate messages he has been receiving toward his wife and children."

A company that produces anti-Trump bumper stickers claims product sales in the Fort Bend County area have skyrocketed as a result of the dispute.

And Fonseca? Her attorney says she's considering filing a civil rights lawsuit against the sheriff and his department. And she has a new bumper sticker, displayed right alongside the old one: "F--- Troy Nehls and f--- you for voting for him."

Try not to dwell on it, sheriff. It's time to fold 'em -- and it's time to walk away.