A high school teacher in California was placed on paid leave after comparing President-elect Donald Trump to Adolf Hitler, the man responsible for the slaughter of 6 million Jewish people.

The teacher has been allowed to return to work after a brief suspension.

According to the San Francisco Chronicle, Mountain View High School history teacher Frank Navarro, who is described as a Holocaust scholar, reportedly made the comparison “in an effort to show students that the 2016 election is a reflection of the past.”

Or, as others might suggest, Navarro had made the comparison in an attempt to show that “history repeats itself.”

A parent reportedly complained about the parallels Navarro drew, which resulted in the school’s principal and district superintendent asking him to leave on Thursday in what they described as a “time out” as they investigated the incident.

Speaking to the San Francisco Chronicle on Saturday, the 40-year veteran of the school said, “this parent said that I had said Donald Trump was Hitler. That’s sloppy historical thinking,” he said.

Yet, Navarro later went on to draw a comparison between Adolf Hitler’s campaign promise to eject foreigners and make Germany “great again” with Trump’s rhetoric about building a wall to keep out illegal immigrants in order to “Make America Great Again.”

Navarro reportedly said, “I think it makes sense. It’s factual, it’s evidence-based. It reminds students that history is real.”

The Chronicle notes that Principal David Grissom and Superintendent Jeff Harding made the decision to place Navarro on temporarily leave, fearing the lesson may have been inappropriate .

However, a Mountain View High alumnus reportedly started a Change.org petition two days later demanding Navarro’s leave be revoked and asking the principal to apologize “for attempting to intimidate a respected educator.”

The petition had garnered over 17,000 signatures as of Sunday evening.

On the petition, alumna Annie Ashmore quoted Mr. Navarro bashing Trump, saying, “In Mr. Navarro’s words, “I feel strongly about this: to stand quiet in the face of bigotry and to turn your eyes away from it is to back up the bigotry, and that’s not what I, or any history teacher, should be doing in our work.”

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