South Carolina Gov. Nikki Haley said Republican presidential candidate Donald Trump should use a more civil tone while campaigning, warning that divisive rhetoric could ultimately lead to violence on par with the 2015 Charleston church massacre.

“I know what that rhetoric can do,” the Republican governor told The Associated Press on Thursday. “I saw it happen.”

Haley spoke to the news agency just weeks before the first anniversary of the June 17, 2015 killing spree in which a white man murdered nine black churchgoers, reportedly because he wanted to ignite a race war.

In the new interview with AP, Haley said Trump supporters aren’t all racists. 

“That’s a different kind of anger,” she told AP. “They’re upset with Washington, D.C. They’re upset nothing’s got done. The way he communicates that, I wish were different.”

Haley first supported Marco Rubio during the primaries. At a campaign stop in Florida, she issued a similar warning over Trump’s divisive language. 

“That is not who we are as Republicans,” Haley said, according to Mother Jones. “And we are seeing a division that is dangerous.”

With regards to Trump, Haley noted:

“We have someone running for president who instead of bringing [people] back together like we did in South Carolina, he’s telling his supporters to punch a guy in the face! He’s telling them if they don’t do the right thing to carry him out on a stretcher. He’s telling them to say, do it again. He’s not denouncing the KKK when this is exactly the same group that protested on my statehouse grounds. We can’t have Donald Trump as president! We can’t.”

After the Florida senator dropped out of the race, Haley endorsed Ted Cruz. Now she has indicated that she will support Trump.

“I have great respect for the will of the people, and as I have always said, I will support the Republican nominee for president,” she told the Post and Courier newspaper last month.