U.S. District Court Judge Gonzalo P. Curiel has been lambasted by Donald Trump a lot lately, as Curiel is presiding over a pair of class-action lawsuits against the candidate and his now-defunct Trump University. Curiel, as it turns out, has had enemies before: namely, one of the most powerful families in the Mexican drug cartel.

As the L.A. Times reports, Curiel was a federal prosecutor from 1989 to 2002. From 1996 until 2001, he was the coordinator of the Arellano-Felix task force, charged with taking down the Arellano-Felix cartel. Also known as the Tijuana Cartel, this was one of the most powerful and notorious groups in Mexico.

An informant claimed that one member, Benjamin Arellano Felix, had put out a hit on Curiel. So, Curiel was put under the protection of U.S. Marshals and forced to move from his San Diego home to a Navy base, and also spent stints of time in San Francisco and Washington. One of the biggest things he did in this case was get cartel official Arturo "Kitty" Paez Martinez extradited in 2001—the first time a Mexican citizen had ever been extradited to the U.S. According to the Times, this would pave the way for the extradition of other traffickers to the U.S.

And to be clear, the head of the cartel, Ramon Arellano Felix, was not the kind of guy you wanted to know, let alone have as an enemy. He is said to have slaughtered 12 people because they were related to a drug dealer who owned him money. He was killed in a shootout with a Mexican police officer in 2002, and brother Benjamin was arrested a few weeks later.

Curiel is presiding over two lawsuits against Donald Trump and Trump University, which several former students allege is nothing but a big scam. The University has not admitted any new students since 2010, when the lawsuit launched, and Curiel is the third judge to preside over the suit, coming on in 2013. Trump has apparently decided to channel his anger over the lawsuits at Curiel himself.

During a recent appearance in San Diego, Trump claimed that Curiel is "a hater of Donald Trump," and has treated him unfairly.

I'm telling you, this court system, judges in this court system, federal court, they ought to look into Judge Curiel. Because what Judge Curiel is doing is a total disgrace, OK? But we'll come back in November. Wouldn't that be wild if I’m president and I come back to do a civil case? Where everybody likes it. OK. This is called life, folks.

He also claims Curiel has an "absolute conflict" because he is Mexican, and therefore, likely has an issue with Trump's plan to build a wall between the United States and Mexico.

In an interview on CNN with Jake Tapper, Trump said:

Jake, I'm building a wall, okay? I'm building a wall. I'm trying to keep business out of Mexico. Mexico's fine...He's of Mexican heritage, and he's very proud of it, as I am of where I come home."

As Tapper pointed out, Curiel was born in Indiana, and is an American citizen. Curiel's parents were Mexican immigrants, but are also now American citizens.

Trump also claims to have thousands of people who called Trump University "fantastic," though some students claim they were strong-armed into providing positive feedback about the school.

Trump and Tapper begin discussing Curiel at the 11-minute mark:

Meanwhile, conspiracy theorist Alex Jones made the following statement: "I'll tell you it's a fair headline to say that this judge is the equivalent of a Hispanic grand dragon." Because of course Alex Jones would say something like that.

Deborah L. Rhode, a professor at Stanford Law School, told the New York Times that Trump's statements are like if someone said Thurgood Marshall—he was the Supreme Court's first black justice—couldn't preside over civil rights cases. "If race were a disqualifying factor, nobody could preside over these cases," she said.

Curiel has made no comment on Trump's remarks, though his office did provide a statement saying judicial rules forbid judges from talking about upcoming cases, according to the L.A. Times.

Muriel went to work with the U.S. Attorney's office in Los Angeles in 2002, and was appointed in 2006 to San Diego County Superior Court by Gov. Arnold Schwarzenegger. President Obama nominated Curiel to serve on the U.S. District Court for the Southern District of California in 2011, and he received commission in 2012. Shortly thereafter, he inherited the Trump case.