PHILADELPHIA (AP) — Witnesses described an ugly scene: Two members of the New Black Panther Party threatening white voters the day Barack Obama was elected president, flinging insults like ‘‘white devil’’ and ‘‘you’re about to be ruled by the black man, cracker.’’

The fallout from the case has become even uglier. Most charges against the men were dropped for lack of evidence, the U.S. Justice Department says. Now a former Justice Department lawyer is accusing his ex-superiors of ignoring white voters’ rights and creating a systematic ‘‘one-way’’ approach in which only minorities are protected.

The claims by J. Christian Adams are the latest installment of a long-running dispute over Justice Department enforcement of the nation’s civil rights laws. It’s a political fight over such volatile accusations as black-on-white racism, double standards and payback — issues that are magnified with black men serving as president and attorney general.

‘‘To some, the civil rights laws are not meant to protect all Americans, they are meant to protect certain Americans,’’ Adams, a conservative who helped prosecute the case against the New Black Panthers, wrote in a June 28 essay on pajamasmedia.com. He quit the Justice Department on May 14.

Adams declined to speak with The Associated Press on Thursday. He told Fox News earlier, ‘‘There is a pervasive hostility within the civil rights division at the Justice Department toward these sorts of cases’’ where blacks are accused of discrimination.’’

Department of Justice spokesman Tracy Schmaler said the law is enforced equally for everyone and that the charges against the New Black Panthers were dropped because they were not supported by the facts or the law.

‘‘We continue to work with voters, communities and local law enforcement to ensure that every American can vote free from intimidation, coercion or threats,’’ Schmaler said.

On Election Day 2008, King Samir Shabazz and Jerry Jackson dressed in black uniforms of the New Black Panther Party for Self-Defense, whose Web site recently made such statements as, ‘‘the white man has kept us deaf, dumb and blind, and used every ‘dirty trick’ in the book to stand in the way of our freedom and independence.’’

The men stationed themselves near the entrance to a polling place in a largely black neighborhood. Shabazz carried a nightstick. Their actions quickly came to the attention of police, who told Shabazz to leave but allowed Jackson, a certified poll watcher, to remain.

Shortly before President George W. Bush left office, the Justice Department filed a civil lawsuit against the two men, the New Black Panther Party and its leader, Malik Zulu Shabazz. The defendants never responded to the government’s lawsuit, which had the same effect as a guilty plea.

Before any penalties could be handed down — and after Obama appointed Eric Holder to run the Justice Department — charges were dropped against everyone but Samir Shabazz. The court prohibited him from displaying a weapon within 100 feet of any Philadelphia polling place through 2012.

The Justice Department has explained this decision by saying that Jackson was a certified poll watcher who did not carry any weapons, that the New Black Panther website denounced the actions in Philadelphia and that the group had no national plan to intimidate voters.

Adams says it should have been an open-and-shut case and that numerous ‘‘career’’ Justice Department attorneys — as opposed to those who come and go with each administration — agreed that the New Black Panthers clearly intimidated voters.

He wrote that some people see selective enforcement of civil rights laws ‘‘as a backdoor way to achieve reparations for slavery and discrimination. If the American public won’t tolerate monetary reparations, which they won’t, then a one-way approach to civil rights laws is seen as the next best alternative.’’

‘‘This aggressive one-way approach toward the civil rights laws is central to understanding why the voter intimidation case against the New Black Panther Party was dismissed by the Obama Justice Department,’’ he wrote.

Adams’ claims are rooted in decades of ideological battles over the Justice Department that were fought as overt racism waned and the wisdom of laws aimed at helping minorities began to be questioned.

Ronald Reagan’s administration drew much liberal criticism for its enforcement priorities, as did Bill Clinton’s from conservatives. Last December, a Government Accountability Office report documented what Democrats called reduced enforcement of major laws against discrimination and voting rights during the Bush administration.

Now it’s the conservatives’ turn.

‘‘There’s a fair amount of evidence, from this case and others, of a belief that these laws should only be used to enforce the rights of minorities,’’ said Jennifer Rubin, a contributing editor at Commentary magazine who has written extensively about the New Black Panther case. ‘‘That’s a matter for public debate, and perhaps great concern.’’