NASHVILLE (AP) — A Tennessee Republican running for U.S. Senate resigned from the board of a brokerage firm after the company expressed support for the Black Lives Matter movement, according to a letter from the candidate.

Bill Hagerty announced he would be stepping down from the board of R.J. O'Brien & Associates in a letter to CEO Gerald Corcoran on Saturday.

Hagerty, who previously served as President Donald Trump's U.S. ambassador to Japan, is running for the seat being vacated by retiring Republican Sen. Lamar Alexander in Tennessee's Aug. 6 primary.

In a May 31 statement posted to Twitter, R.J. O'Brien & Associates said it "stands proudly with the African American Community in support of equality & peace," according to the Chattanooga Times Free Press. The tweet, which has since been deleted, included the hashtag #BlackLivesMatter, the news outlet said.

"I cannot in good conscience remain affiliated in any way with the promotion of a radical political movement," Hagerty wrote in his resignation letter.

The Black Lives Matter movement emerged amid anger over the acquittal of George Zimmerman, the Florida man who shot and killed 17-year-old Trayvon Martin in 2012. The slogan "Black lives matter" soon became widely heard at protests and has become a rallying cry during global demonstrations against police brutality and racial injustice that were sparked by the death of George Floyd in May.

Floyd, a handcuffed Black man, died after a white Minneapolis police officer pressed a knee against his neck for several minutes as Floyd lay face down on the ground.