More than 800 people signed a petition started by a Texas Southern University student who opposed the university's invitation to the Republican senator to speak at Saturday's graduation in Houston.
Texas Southern University is one of the largest historically black universities in the country and confers the fourth-largest number of doctoral and professional degrees to African Americans.
A Republican senator's scheduled commencement address at a historically black university has been cancelled, amid fears of opposition and threats of protest from students.
The petition cited Cornyn's votes to confirm Attorney General Jeff Sessions and Education Secretary Betsy DeVos as two of US President Donald Trump's cabinet appointees.
The university said it had asked Cornyn to visit at a later date. "Cornyn, agree that the primary focus of commencement should be a celebration of academic achievement". John Cornyn would be speaking at their graduation. It also comes weeks after protests led a student group at the University of California at Berkeley to pull the plug on a speech by conservative commentator Ann Coulter.More news: Canada - Emergency in Montreal for heavy floods
"This was within the president's authority, but it is really important, it is absolutely essential, that we have a new Federal Bureau of Investigation director that shares the confidence, not only of the president but of Congress and the American people", Cornyn said Wednesday on Fox News.
The students' petition referenced Cornyn's support of stricter voter ID laws, as well as his low rating with the NAACP.
If Cornyn were selected, there likely would be Democratic concern about handing over the nation's premier law enforcement agency to a Republican who - despite being considered an affable senator - has served as a prominent partisan attack dog.
Disclosure: Texas Southern University has been a financial supporter of The Texas Tribune. The protesters' plan, she said, was to stand up silently and face away when Cornyn spoke. A complete list of Tribune donors and sponsors can be viewed here.