“The Department of Justice is now moving away from that, and its emerging view of civil rights is a dangerous trend, inconsistent with legal history, and a disturbing manifestation of President Trump,” Mr. Siegel said.

The Asian-American suit against Harvard, which argues that the school’s admissions policies are discriminatory, is positioned to help one minority group, but former Justice Department attorneys worry that it could ultimately weaken a legacy of the civil rights era that has been used to expand opportunities to other underrepresented minorities.

The Justice Department’s support of that suit “is a distortion of the law and repeated rulings from the United States Supreme Court,” said Anurima Bhargava, an attorney who worked in the department’s civil rights division. “It undermines schools’ efforts to bring students of different backgrounds together.”

The department’s shift in how it regards civil rights has happened quickly and often in lock step with other parts of the administration. The Leadership Conference, a civil rights advocacy group, counts at least 95 instances in which the administration has taken a stance antithetical to longstanding views on civil rights and civil liberties. Those efforts include chipping away at the rights of immigrants and disadvantaged populations, including prisoners.

The moves “are happening at such a fast clip that it is hard to keep track of all of them,” said Janai Nelson, a lawyer at the NAACP Legal Defense and Educational Fund.

The department’s shift in priorities was on display at the end of July, when Mr. Sessions hosted a religious freedom summit to celebrate what he called the country’s “first freedom.”

Speakers included the deputy attorney general, Rod Rosenstein, politicians, leaders from many faiths, conservative advocates and Jack Phillips, the owner of the Masterpiece Cakeshop, whose refusal to create a wedding cake for a gay couple on religious grounds was upheld in June by the Supreme Court.