Attorney General Eric Holder, a longtime target of Republicans who have tried to force him out of office, now faces the prospect of angering liberal supporters when the Justice Department decides whether to file federal charges in the Trayvon Martin killing.
Civil rights groups are planning nationwide vigils, and more than a million people support an online petition drive calling for admitted shooter George Zimmerman to face federal charges in the February 2012 killing.
Holder confronted that political pressure Tuesday in a speech to the NAACP, which is conducting the petition drive.
He repeated his pledge for a full investigation of Martin's death in the aftermath of Zimmerman's acquittal on murder and manslaughter charges by a Florida court, saying the Justice Department "will continue to act in a manner that is consistent with the facts and the law. We will not be afraid."
But he was careful to avoid any promise or hint of federal charges. Instead, Holder took aim at "stand your ground" laws like the one in Florida that have expanded the right to respond with deadly force if attacked outside the home.
Those laws "try to fix something that was never broken" and "senselessly expand the concept of self-defense and sow dangerous conflict in our neighborhoods," he said.
"By allowing -- and perhaps encouraging -- violent situations to escalate in public, such laws undermine public safety," Holder said in his first public comment on legislation that more than 30 states have passed in some form.
"We must stand our ground to ensure that our laws reduce violence and take a hard look at laws that contribute to more violence than they prevent," he added.
Zimmerman's lawyers didn't invoke Florida's "stand your ground" law in court, but it was included in the instructions to the jury that acquitted him. Florida Gov. Rick Scott's office reaffirmed his support for the law Tuesday afternoon, saying a task force set up by his office reviewed the statute after Martin's death.
"The task force recommended that the law should not be overturned, and Governor Scott agrees," Scott spokeswoman Melissa Sellers said in a written statement.
Chris W. Cox, executive director of the National Rifle Association's Institute for Legislative Action, similarly disagreed with Holder.
"The attorney general fails to understand that self-defense is not a concept, it's a fundamental human right," he said in a statement. "To send a message that legitimate self-defense is to blame is unconscionable, and demonstrates once again that this administration will exploit tragedies to push their political agenda."
Holder's focus Tuesday on a broader legal issue avoided the difficult decision he faces over whether to bring federal criminal charges.
Legal experts say federal charges against Zimmerman are unlikely.
Because Zimmerman is a private citizen, he can only be charged with a hate crime in terms of civil rights violations under federal law, said David Weinstein, a former federal prosecutor in Florida who now is in private practice.
To successfully prosecute Zimmerman, the Justice Department would have to show that Zimmerman "caused the death of Trayvon Martin solely motivated by/because of his race or color," Weinstein told CNN in an e-mail. "This element was absent from the state trial and quite frankly doesn't exist."
CNN Legal analyst Paul Callan agreed Monday that federal prosecutors are "in sort of a tough spot."
The hate crimes statute is generally applied to cases involving police officers or other government agents, Callan said, adding that using it in a case involving a lone private citizen is "very, very rare and I think in this case, it's going to be very hard to prove."
Sources told CNN Monday that Justice Department officials were reviewing trial evidence to determine if such a case was winnable. The sources made clear that Holder's department would only file charges if officials believe they can secure a conviction.
If Holder decides not to bring a federal case against Zimmerman, he will disappoint liberal supporters who contend the Martin killing was a civil rights violation.
The nation's first African-American attorney general has been popular with the political left for his support of gay marriage and challenges to GOP efforts to change voting laws. At the same time, his policies have made him a political lightning rod for conservatives.
Holder was censured last year by the Republican-led House over complaints that he failed to fully cooperate with a congressional investigation of the botched "Fast and Furious" gun-walking operation. He called the episode a politically motivated effort to discredit him.
Last year, Holder himself raised questions about possible federal charges against Zimmerman, a neighborhood watch volunteer, who killed Martin during an altercation as the unarmed teenager was walking in the community.
"For a federal hate crime, we have to prove the highest standard in the law," Holder said in April 2012, 45 days after Zimmerman shot Martin in what was depicted by civil rights groups as a racially motivated killing.
In words that now sound prescient, Holder described to reporters that day how "something that was reckless, that was negligent does not meet that standard."