The leading candidate in the crowded Los Angeles school board race issued a public mea culpa on Tuesday for his problematic social media activity that included siding with antisemitic sentiments and liking pornographic images.

Kahllid Al-Alim’s social media activity could derail his campaign to become a school board member. He had managed to gain endorsements from the influential United Teachers Los Angeles and the L.A. County Federation of Labor unions but faces an uphill battle following the damning discovery of social media posts that have called his judgment into question.