A California professor is facing a backlash over a social media rant in which he calls Sen. John McCain, who is battling a brain tumor, a “war criminal.”

KGTV reports that those who have criticized San Diego State University professor Jonathan Graubart for his comments include students enrolled at the college.

“I find myself annoyed at the groundswell of good wishes for John McCain after his diagnosis of glioblastoma and have been thinking through why," Graubart wrote on Facebook Friday, the same day McCain went public with the illness.

Graubart then made an analogy about elite lives and ordinary lives and circled back to McCain.

“McCain is a war criminal and, more to the point, someone who as a politician has championed horrifying actions and been lousy on state commitment to public health," the professor said. "So dying or not, he's a risible public figure (I have no idea what he is like on the personal level and don't care).”

Graubart concluded by saying, “But ultimately what troubles me is the urge to send such well wishes to an utter stranger as it reinforces the notion that some lives are more important than others. There are lots of people with glioblastoma and who have died from it (including my mother 20 years ago).”

McCain's doctors found the tumor after the senator underwent a procedure to remove a blood clot from above his left eye.

SDSU student Ben Dilbeck told the station Graubart’s comments were shocking.

“I would never wish cancer upon my worst enemy and then to be annoyed by people just wishing you the best for having cancer, I just thought it was totally inappropriate,” he said.

The station also interviewed former SDSU student Colby Tunick who read what the professor wrote while in Prague.

“I think I was a little disturbed, to be quite honest,” Tunick told the station, via Skype. "You may disagree with someone politically, morally, philosophically, but you don’t wish someone harm.”

He also said he wasn’t surprised about the post.

“He has told me that he thinks it’s his job as an academic to stir controversy and he normally does that through Facebook," Tunick said.

But some people defended Graubart, saying he’s entitled to speak his mind. They described him as a man of integrity and intelligence.

The College Republicans of SDSU, a student group, posted a statement on social media Sunday condemning Graubart’s remarks.

“As an academic authority at SDSU, Dr. Graubart’s sickening lack of respect toward Senator McCain will not be tolerated by our organization and should not be tolerated by university administration,” the statement said.

An SDSU spokesperson told KGTV the university does not have a social media policy for faculty and staff.

“As a public institution, we do not and cannot regulate the private speech of students, faculty or staff,” the spokesperson said. “However, that should not imply the university’s endorsement of any particular viewpoint.”

Graubert issued a statement to Fox News explaining his post.

"It bears emphasis that this was on my personal Facebook post, which rarely gets many readers, even for the ones I make public," he said. "Hence, I was not writing it with a large public in mind and therefore this was written in an off-the-cuff manner, rather than with careful deliberation."

Graubart’s SDSU bio says his specialty as a professor are the areas of international relations and international law. It says he is a former San Francisco lawyer who worked in the Treasury Department when Ronald Reagan was president.