Drexel University associate professor of political science George Ciccariello-Maher has a long history of espousing racist views towards white people on Twitter and has at times supported genocide.

Cicariello-Maher, a white man who specializes in race and racism among other topics, has been the subject of criticism from media outlets and social media users after he tweeted on Saturday, “All I Want for Christmas is White Genocide.” He subsequently deleted the tweet and brushed it off as a joke, saying that “White isn’t a race.” (RELATED: University Professor: I Want ‘White Genocide’ For Christmas)

However, Cicariello-Maher’s view that “white isn’t a race” doesn’t match up with his past tweets. On Sunday, Ciccariello-Maher said that the massacre of whites during the Haitian Revolution was a “good thing.” During the Haitian massacre in 1804 as many as 4,000 whites were killed.

Ciccariello-Maher’s anti-white tweets, however, did not start this weekend. On Feb 3, 2013, the Drexel professor said that “Yacub made a lot of white folks.” According to Nation of Islam theology, Yacub is a black scientist who created the white race to be a “race of devils.”

Then on June 8, 2015, Ciccariello-Maher said, “Abolish the White Race.” A little over a week later, the Drexel professor said that Charleston church shooter Dylann Roof “simply put into practice what many white Americans already think.”

Ciccariello-Maher also tweeted in Sept. 2016 a purported exchange between him and his son: “Son: If I was a slave, I’d bake a cake & put a potion in it & the white people would steal it Me: What would the potion do? Him: Kill them,” the Drexel University professor wrote.

Just this past week, in response to a viral video claiming to show two men kicked off a plane for speaking Arabic, Ciccariello-Maher wrote, “#Gulag these Racist Crackers.”

Ciccariello-Maher, who describes himself as a communist, joined Drexel University in 2010. Drexel University said in a statement Sunday afternoon: “While the University recognizes the right of its faculty to freely express their thoughts and opinions in public debate, Professor Ciccariello-Maher’s comments are utterly reprehensible, deeply disturbing, and do not in any way reflect the values of the University.”

“The University is taking this situation very seriously. We contacted Ciccariello-Maher today to arrange a meeting to discuss this matter in detail,” the statement continued on to say. Ciccariello-Maher provided a statement to TheDC Monday in which he said white genocide is “an imaginary concept” and that his tweet Saturday was satirical.

Ciccariello-Maher took issue with Drexel University’s statement. “While Drexel has been nothing but supportive in the past, this statement is worrying. While upholding my right to free expression, the statement refers to my (satirical) tweets as ‘utterly reprehensible.'” the Drexel University professor wrote. “White supremacy is on the rise, and we must fight it by any means. In that fight, universities will need to choose whether they are on the side of free expression and academic debate, or on the side of the racist mob.”

He responded to TheDC on Tuesday about his tweet wishing to “abolish the white race,” and said, “the idea that there is a white ‘race’ is a biological fiction, it doesn’t exist scientifically. It does exist politically, as a privileged position of power to be abolished.”

The Drexel professor has authored three books, and according to his biography he has written for The Huffington Post, The Nation, Salon, and the Philadelphia Inquirer.