Tucked into Julián Castro’s police overhaul plan is a proposal to pull back on a judicial doctrine that is regularly used to shield officers from civil lawsuits for brutality or misuse of deadly force.

Castro has called for reforming and restricting the "qualified immunity" defense for law enforcement officers in the policing reform plan he released on Monday.

That call has drawn the attention of the liberal group Demand Justice, which is planning a digital ad campaign to thank Castro for taking the stand and to call on other 2020 Democratic presidential candidates to do the same.

The ads, which are to begin Monday, will run in the early primary and caucus states of Nevada and South Carolina.

“Castro is the only 2020 candidate so far to even mention it,” said Brian Fallon, Demand Justice’s executive director. The ads are not endorsements and are not coordinated with the campaign.

The qualified immunity defense essentially gives the benefit of the doubt to law enforcement officers who are sued over actions that took place while carrying out their official duties. It extends the protections from being sued for unconstitutional conduct to government officials.

“Issues like qualified immunity have long been a roadblock to accountability in our criminal justice system,” Castro told NBC News. “I’m proud to put forward a People First Policing plan to ensure officers aren’t above the law and states can’t turn a blind eye to police misconduct.”

Fallon’s group has also run digital ads praising 2020 candidates Sens. Kamala Harris and Kirsten Gillibrand after they pledged to oppose all of President Donald Trump’s nominees to the federal appeals courts and similarly called on other Democrats to do the same.

Greater scrutiny for qualified immunity

Congress has not tried to tackle qualified immunity in legislation, Fallon said, and it has expanded while Justice John Roberts has been the Supreme Court chief justice, "preventing victims of police brutality from getting justice."

The qualified immunity defense is getting greater scrutiny of late, particularly since Supreme Court Justice Sonia Sotomayor wrote a passionate dissent in the case of the 2010 police shooting of Amy Hughes outside her home. The court ruled last year that the officer was immune from being sued.

Sotomayor said the ruling transformed the doctrine of qualified immunity "into an absolute shield for law enforcement officers.

She wrote it “sends an alarming signal to law enforcement and the public. It tells officers that they can shoot first and think later; and tells the public that palpably unreasonable conduct will go unpunished.”

The issue also is being raised in a case now before the Supreme Court: a lawsuit filed by the parents of Sergio Hernández Güereca, a 15-year-old Mexican teen who was killed when a Border Patrol agent fired several shots across the U.S.-Mexican border. The U.S. 5th Circuit Court of Appeals ruled his family can’t sue because he was killed in another country.

Fallon said even though many elected officials are not talking about qualified immunity, “there is an emerging bipartisan consensus” that it needs to be reformed.

The liberal American Civil Liberties Union and the libertarian Cato Institute have filed “friend of the court” briefs in a separate case petitioning the court to get rid of qualified immunity, Fallon noted.

It’s not clear that there is a majority against that idea, he said. Justice Clarence Thomas expressed “growing concern with our qualified immunity jurisprudence” in an opinion.

“In an appropriate case, we should reconsider our qualified immunity jurisprudence,” Thomas said.

The Demand Justice ads feature a graphic with screen captures of Castro and the Supreme Court building. The text on the graphic says, "Julián Castro is protecting our rights against the Supreme Court."

The ads will run in English and Spanish for two weeks on Facebook and Twitter. Fallon estimated the group would spend about $25,000 on the ads.

Latino turnout is growing in Nevada. In South Carolina, the majority of the Democratic electorate is African American.

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