Former Oklahoma state Sen. Ralph Shortey, who led President Trump's campaign in that state, will plead guilty to a child sex trafficking offense before an Oklahoma City federal court later in November after he offered to a pay a 17-year-old boy for sexual "stuff" in March.

Shortey's defense attorney, Ed Blau, made the plea deal on behalf of his client so U.S. prosecutors would drop three child pornography counts against him, according to NewsOK.com.

"It is in my best interest and in the best interest of my family," Shortey, a married, father-of-four, wrote on plea paperwork signed Monday.

The Republican — who was first elected in 2010, despite once aspiring to be a missionary — was investigated by police and the FBI after he was found with the teenager at the city's Super 8 on March 9 thanks to a tip from the victim's girlfriend.

The pair had met through a Craigslist ad in 2016, a platform through which Shortey often used a fake names "for illicit and illegal sexual interests or encounters," an FBI agent wrote in a court affidavit.

Shortey and the teen discussed sex using the messaging app Kik before going to the hotel, including the victim saying he needed "money for spring break," per police reports.

Shortey told the boy that he didn't "really have any legitimate things" he needed "help with right now."

"Would you be interested in 'sexual' stuff?" he wrote.

Shortey will serve at least 10 years behind bars, but U.S. District Judge Timothy DeGiusti could punish him with life in prison during a sentencing hearing in 2018.