Donald Trump has branded him a "hater," "very hostile" and "Mexican."
U.S. District Judge Gonzalo Curiel, who's presiding over two of the three lawsuits against Trump University in San Diego, is clearly now in the cross hairs of the bombastic presumptive Republican presidential nominee.
But Curiel is no stranger to being targeted — and in the 1990s he was even reportedly on the hit list of a Mexican drug cartel.
On the campaign trail last Friday, Trump lobbed a number of verbal assaults against Curiel, whom Trump slammed for his handling of the case in which his namesake online school is accused of defrauding students.
"The judge was appointed by Barack Obama," Trump told a campaign rally on the same day as a hearing in the case. "I mean frankly, he should recuse himself because he's given us ruling after ruling after ruling, negative, negative, negative."
The judge appeared to take a swipe at Trump that same day by ordering internal Trump University documents to be released as part of a class-action lawsuit. (He is prevented by a judicial code of conduct from responding publicly to the verbal attacks.)
In deciding to release the documents, Curiel simply noted that Trump "has placed the integrity of these court proceedings at issue."
It's a move that will likely keep Curiel at odds with Trump. In fact on Thursday, Trump told The Wall Street Journal that he believes the judge has an "inherent conflict of interest" simply because of his Mexican heritage and the candidate's stated plan to build a wall on the southern border.
Here's what else is known about the veteran jurist:
He's the son of immigrants.
Curiel was born in East Chicago, Indiana, in 1953, according to the Federal Judicial Center.
During a Senate confirmation hearing in 2012 regarding his appointment as a U.S. District judge, Curiel was described as the son of Mexican immigrants, whose parents came to the United States with an elementary school education.
"My parents came here from Mexico with a dream of providing their children opportunities and they've been able to do that with the opportunities that this country has to offer," Curiel told the Senate committee.
Trump had referred to Curiel as "Mexican" last week — a description that some Latinos say was meant to be disparaging.
He worked his way up to a judgeship.
After earning his law degree from Indiana University in 1979, Curiel spent the next 10 years in private practice in Indiana and California.
He then served as an assistant U.S. attorney in California's Southern District, and worked in the Narcotics Enforcement Section before he was appointed in 2006 by then-Gov. Arnold Schwarzenegger as a San Diego Superior Court judge.
He oversaw domestic violence cases as well as family court and civil cases.
In 2011, Obama first nominated him to a district judgeship representing the Southern California district in San Diego. He was confirmed the following year by the Senate. He tried over 300 cases at that point, mostly in front of a federal criminal jury.
Before his nomination, he was lauded for his years on the bench.
"He comes to us, in short, as a nominee with impressive — indeed, extraordinary — record of experience, public service, and I look forward to his swift confirmation," Sen. Richard Blumenthal, D-Conn., said at the confirmation hearing.
Curiel is now one of about 124 Hispanic judges on a federal court, according to the Federal Judicial Center.
The Hispanic National Bar Association has come to Curiel's defense with Trump's latest comments.
"Donald Trump continues to belligerently inject racial bias and divisive politics into his legal battles over the now-defunct Trump University," association President Robert T. Maldonado said in a statement Wednesday. "It shows a dangerous disregard and disrespect for separate and coequal branches of government."
He has described his philosophy as a judge as one that follows precedent.
During his confirmation hearing in 2012, he told the Senate: "As a trial judge I recognize that I'm not there to make the law, I'm not there to interpret the law, I'm there to follow the law as established by the precedent of our Supreme Court."
He said that if he were confirmed as a District Court judge, he would be bound by the opinions of the Circuit Court and the Supreme Court.
"I've done that in terms of following precedent in my present position, and I would be in a position to continue to do that," he said, according to a transcript of the hearing.
He was targeted by the Tijuana drug cartel.
When Curiel was part of Narcotics Enforcement, he helped to bring down the Mexican criminal organization run by Benjamín Arellano Félix, who was arrested in 2002 and convicted of running a violent and deadly drug cartel between the U.S. and Mexico.
Before Félix's arrest, the Los Angeles Times reported that Curiel had been a possible target by the cartel when a top lieutenant was arrested and claimed in a bugged conversation that he was given the go-ahead to assassinate the U.S. prosecutor.
Curiel, who was involved in the extradition of cartel henchmen, was reportedly placed under tight security.
In discussing the case with The New York Times in 2002, Curiel didn't mention the threats against him, and said that it was useful that he and other prosecutors were of Mexican descent and could speak Spanish.
"When it comes down to it, this involves the country of our parents," Curiel told the newspaper.