In a motion filed in Federal District Court in Montgomery, Ala., the center’s lawyers said that a fraud investigation looking into whether the center had cheated its donors by paying secret informants inside extremist networks had essentially been lying dormant since Mr. Trump’s first term in the White House. The inquiry was only reawakened and an indictment filed, the lawyers said, after Mr. Trump returned to office vowing to seek vengeance on his adversaries.
“The charges against the S.P.L.C. were a foregone conclusion based on prosecutorial vindictiveness — driven by the White House and F.B.I. leadership’s retribution campaign — rather than the result of a good faith examination of the evidence,” they wrote.
The motion in the center’s case was the latest in a growing series of similar efforts by defense lawyers across the country to accuse the Justice Department under Mr. Trump of vindictively using its vast law-enforcement powers to prioritize the president’s political imperatives above the pursuit of actual justice.
Bryan Fair, the center’s interim president and chief executive, said the civil rights group would continue to defend itself against the charges.
“For weeks, we have been arguing against these false allegations levied against the S.P.L.C. — an organization that for 55 years has stood as a beacon of hope fighting white supremacy and various forms of injustice to create a multiracial democracy where we can all live and thrive,” Mr. Fair said. “The government can’t prosecute the S.P.L.C. as payback for its protected speech — it violates basic constitutional rights.”
The Justice Department did not immediately respond to a message seeking comment.
The claims by lawyers for the Southern Poverty Law Center were a reminder of how often Mr. Trump’s own words have been used against him in court and in court filings.
In their motion, the lawyers told Judge Emily C. Marks, a Trump appointee who is handling the case, how Mr. Trump, in a social media message shortly after the indictment was returned, had accused the center of being “one of the greatest political scams in American History” and somehow connected the group’s work to his defeat in the 2020 election.
The lawyers asserted that some of the most senior officials in the Justice Department had also disparaged the center.
That same day, Mr. Blanche, one of the president’s former defense lawyers, told Fox News that the department had no information to suggest that the center had shared any of the information it gleaned from its informant program with law enforcement. But in fact well before the charges were filed, lawyers for the center informed Kevin P. Davidson, the acting U.S. attorney for the Middle District of Alabama, about two cases in which the center had provided tips from informants to the Justice Department, resulting in criminal charges.
In October, Kash Patel, the director of the F.B.I., announced that the bureau was severing its ties with the center, claiming that it “long ago abandoned civil rights work and turned into a partisan smear machine.” Around the same time, Mr. Patel also cut the bureau’s ties with the Anti-Defamation League, a group that fights antisemitism.
The center’s lawyers acknowledged that in 2019 or 2020, during Mr. Trump’s first term, federal agents interviewed at least two former confidential informants in the covert program and at least one former employee. The agents also subpoenaed some of the center’s bank records, apparently examining the same allegations of defrauding donors that formed the basis for the indictment filed last month.
“Whatever its genesis or focus, the earlier inquiry resulted in no charges being brought,” the lawyer wrote. “But from the start of the second Trump administration, targeting groups like the S.P.L.C. became a priority.”
The lawyers suggested that the renewed investigation could have stemmed from National Security Presidential Memo 7, an order Mr. Trump issued calling for sweeping inquiries of left-wing groups in the wake of the assassination last September of the conservative activist Charlie Kirk. The directive, the lawyers said, was “plainly focused on attacking civil rights organizations who engaged in political speech with which President Trump disagrees.”
“The record and timeline of what the S.P.L.C. has done and said carrying out its mission, combined with the president’s criticisms that resulted in the indictment in this case, demonstrate that the S.P.L.C. is being punished for repeatedly speaking out against President Trump’s policy choices and for having criticized his political goals and allies,” the lawyers wrote.