MERRILLVILLE Fellow Republican Donald Trump's verbal attacks on U.S. District Judge Gonzalo Curiel are "way out of bounds," Indiana Attorney General Greg Zoeller said Monday.

Zoeller, in an exclusive interview with The Times, said the presumptive GOP nominee's remarks about Curiel's ethnic background threaten to undermine Americans' faith in the judicial system.

Trump has repeatedly said Curiel is biased against Trump, because Curiel is "of Mexican heritage." Curiel is presiding over one of the class-action lawsuits targeting Trump University.

Zoeller said every attorney, as an officer of the court, is obligated to publicly denounce Trump's remarks about the East Chicago native.

On Thursday, Trump tweeted that Curiel is a "very biased and unfair judge."

Trump's attorneys should have shut him down immediately, Zoeller said, because those are dangerous remarks.

"Our institutions are all under attack," Zoeller said. "Without the rule of law, you've got chaos, a point that needs to be remembered.

"If there's a legitimate question of bias, there is a professional way to raise that without showing disrespect for a judge and the system generally. This is nowhere close."

Every attorney should say this is out of bounds, he said. Zoeller hopes the American Bar Association will become vocal.

"The whole system is based on a trust of the process, so we all have an obligation to do justice. It's not just win at any cost," Zoeller said.

"I'm very sensitive to this, and I'm upset that members of the profession have not all come out and said this is what we don't allow. We would all like more civility, that's what we're shooting for, and this is going in the wrong direction."

Zoeller has worked with Mexican prosecutors and judges as they move from the old Spanish Inquisition judicial process, where charges and testimony are on paper, to the more open process followed in the United States, where defendants can meet their accusers face to face.

Mexicans had lost faith in their system, which is why the judiciary there is changing to the U.S. methods.

Americans need to retain their faith in the judicial system here, he said, and that begins with showing respect for judges and other aspects of the process.

"You have to show your respect for the court," he said.

Zoeller isn't trying to persuade fellow attorneys general across the country to speak out against Trump, and he acknowledges that with Curiel being a fellow Hoosier, Zoeller might have more urgency than others to speak in his defense.