MILWAUKEE — Milwaukee County Sheriff David A. Clarke Jr. — the controversial, Stetson-wearing official who rose to national prominence with his no-holds-barred conservative rhetoric — resigned his office Thursday. 

Clarke, who is in his fourth term, submitted a resignation letter to Milwaukee County Clerk George Christenson on Thursday afternoon. The sheriff was attending the convention of the National Fraternal Order of Police in Nashville and could not be reached for comment. 

“Pursuant to Wisconsin Statute 17.01, this communication is submitted as the notice of my resignation as Sheriff of Milwaukee County commencing Aug. 31, 2017, at 11:59 p.m.,” stated Clarke’s resignation letter. 

He has not said what his plans are.

The news of the resignation was first reported by conservative talk show host Mark Belling. 

Gov. Scott Walker will appoint Clarke’s successor, but the process won’t begin until the governor’s office receives the sheriff’s resignation letter. 

Once that happens, the governor will seek applications, a process that usually takes a couple of weeks, and then begin interviewing candidates. Applicants must live in Milwaukee County to be appointed to the post. 

Clarke’s successor will serve until the end of the current term in 2018.

The son of a Korean war veteran, Clarke is a lifelong Milwaukee resident, growing up in Berryland, a housing project on Milwaukee’s far north side, before the family moved to a home a few blocks away. 

Clarke has been in law enforcement through most of his adult life. He joined the Milwaukee Police Department in 1978, serving as a patrolman for 11 years, being promoted to homicide detective and rising to captain in 1996.

He was catapulted into the job of Milwaukee County sheriff after the resignation of Lev Baldwin. Ten people applied for the opening, and then-Gov. Scott…