WASHINGTON (Reuters) - A Drexel University professor, whose tweet that he wanted “white genocide” for Christmas sparked a firestorm of criticism from the school and social media, said on Tuesday that administrators supported his right to take part in political debate.

George Ciccariello-Maher, a white associate professor of history and politics at the Philadelphia university, has said his Christmas Eve posting of “All I Want for Christmas is White Genocide” on Twitter was aimed at poking fun at white supremacists.

He is an expert on Latin American social movements with about 10,000 Twitter followers.

But his attempt at satire triggered a backlash from conservative websites, with some online comments calling for him to be fired or commit suicide. Drexel on Sunday called his tweet “utterly reprehensible” and said it would meet with him to discuss it.

Ciccariello-Maher said in an email that he had spoken with Drexel administrators by phone about the tweet.

They “reiterated their support for faculty who participate in vigorous public debate, as well as concern for the safety of myself, my family, and others in this unpredictable post-election climate,” Ciccariello-Maher said.

Representatives for the school did not respond to requests for comment.

“White genocide” is a conspiracy theory promoted by white nationalists who contend that majority-white countries promote low fertility and immigration to wipe out the white population.

Bret Grote, Ciccariello-Maher’s lawyer, said Drexel’s criticism was in response to an online smear campaign by far rightists emboldened by the election of Republican Donald Trump as president.

Drexel, a private school with about 26,000 students, will not discipline Ciccariello-Maher because of his rights to free speech and academic freedom and the political content of his tweet, Grote said.

Ciccariello-Maher “is taking a very consistent and principled opposition to those whose identity, ideology and political platform is based on the systematic suppression of the rights and humanity of people of color,” he said by phone.

Condemnation lit up Twitter and Facebook after such conservative news sites as Breitbart News and The Daily Caller picked up Ciccariello-Maher’s tweet.

On Facebook, Liens Naimad wrote, “You can begin the ‘White Genocide’ by killing yourself, honky!” The Conservative Choice said: “Another left-wing Social Justice Warrior white person who hates white people to the point of wanting them genocided, why am I not surprised.”

Ciccariello-Maher has also drawn online support, with a Change.org petition backing him generating about 7,400 signatures by Tuesday.