Sen. Bob Corker slammed President Donald Trump’s handling of the racially motivated protests in Charlottesville, Virginia, charging that the President “has not demonstrated he understands the character of this nation.” The Tennessee Republican told reporters in Chattanooga, Tennessee, on Thursday that he thinks there must be “radical changes” within the White House. “The President has not yet been able to demonstrate the stability nor some of the competence that he needs to demonstrate in order to be successful,” Corker said, according to a video posted by local news website Nooga.com. “He has not demonstrated that he understands what has made this nation great and what it is today, and he’s got to demonstrate the characteristics of a president who understands that,” Corker added. Corker is the latest Republican senator to criticize Trump’s handling of the Charlottesville protests. Trump attacked two other Republican senators — Lindsey Graham of South Carolina and Jeff Flake of Arizona — on Twitter on Thursday morning over their criticisms of him. Corker has maintained a collegial relationship with Trump and his administration, and he has spoken regularly with both the President and Secretary of State Rex Tillerson. At the same time, he spearheaded the Russia sanctions legislation Trump reluctantly signed into law earlier this month, and in May, he said the White House was in a “downward spiral.” Corker on Thursday declined to detail what he meant by “radical changes” and said he did not want to discuss specific officials in the White House. “There just needs to be a different approach,” he said. But he took aim at Trump for his Tuesday comments that played to the extremist wing of his political base and sparked condemnation from Republican lawmakers as well as business leaders and others. “Helping inspire divisions because it generates support from your political base is not a formula for causing our nation to advance, our nation to overcome the many issues we have to deal with right now,” Corker said. CORRECTION: This story has been updated to add a dropped phrase back into Corker’s quote.