Graduating seniors at Bethune-Cookman University turned their backs in protest against US Education Secretary Betsy DeVos at the start of her commencement speech at the historically black institution.
Some graduating students shouted "Liar!" and "Just go," as she powered through her speech on Wednesday at the Florida university.
"Let's choose to hear one another out," DeVos said, reading her prepared text in a measured tone despite continuing waves of boos, catcalls and scattered applause.
As the crowd kept trying to shout her down, university president Edison Jackson briefly took over the microphone to sternly lecture the class of 2017.
"If this behaviour continues, your degrees will be mailed to you. Choose which way you want to go," Jackson warned.
DeVos alienated many African-Americans in February when she described historically black colleges as "real pioneers when it comes to school choice".
After a storm of criticism, she acknowledged that these colleges were "born, not out of mere choice, but out of necessity, in the face of racism".
In her keynote, DeVos repeatedly praised the school's founder, Mary McLeod Bethune, as someone who "refused to accept systemic and repulsive racism," and had "the courage to change old ideas".
"I am here to demonstrate in the most direct way possible that I and the administration are fully committed to your success and to the success of every student across this great country," she said.
President Donald Trump's nomination of DeVos, a Republican fundraiser with no classroom experience, was so controversial that Vice President Mike Pence had to cast a tie-breaking vote for her Senate confirmation.