A Republican gubernatorial candidate in Michigan is facing backlash after voicing unsubstantiated conspiracy theories about American Muslims on Michigan’s Senate floor, but some of his GOP colleagues seem determined to sidestep the debacle.

Patrick Colbeck, a second-term state senator, is doubling down on comments he made Thursday in the Michigan Senate alleging that the Muslim Brotherhood, an Islamist group with roots in Egypt, is waging “civilization jihad” in the United States ― which has been debunked as a conspiracy theory. He also repeated unfounded speculation that Abdul El-Sayed, a Muslim American doctor running for the Democratic nomination, has ties to the Muslim Brotherhood.

The Muslim Brotherhood has influence throughout the Middle East. U.S. foreign policy and counterterrorism officials have been highly critical of the organization and its ideology but have generally not viewed it as a threat to national security. However, advocates for American Muslims have long insisted that conspiracy theories about the Muslim Brotherhood are promoted to foster mistrust of legitimate Islamic organizations working to advance their communities’ interests.