WASHINGTON – Like PresidentDonald Trump's other efforts to fire federal workers, his attempt toremove Federal Reserve governor Lisa Cookcould soon end up at theSupreme Court. Trump is testing the limits of his executive power, including over agencies designed to be insulated from political influence. In May, an ideologically divided courtsaidTrump could fire without cause members of two such agencies that deal with labor issues. But the majority also notablysaidthe Federal Reserve is different from the National Labor Relations Board and the Merit Systems Protection Board. The court called the central bank a "uniquely structured, quasi-private entity," signaling the justices would likely uphold the constitutionality of the bank's for-cause removal protections. Trump, however, says he has sufficient justification. He alleged Cook committed mortgage fraud by signing documents that declared homes in Michigan and Georgia as her primary residence. More:Trump said he fired Fed governor Lisa Cook. But did he have a good reason? Cook's lawyer, Abbe Lowell, said the firing "lacks any factual or legal basis." Cook plans to challenge the move in court. If a judge lets Cook stay in her job while the case is being litigated, Trump is likely to ask theSupreme Courtto intervene as he has in other firing disputes. Trump's move is unprecedented in the Fed's 111-year history, another reason the high court could weigh in. Plus, the law is not specific about what evidence of wrongdoing is required for removal. There's also the question of whether Trump is masking the real reason he wants to get rid of Cook. "An underlying challenge is that given his recent attacks on the Fed, it seems clear that the primary reason that President Trump is seeking to fire Governor Cook is that he disagrees with her on policy," Kathryn Judge, a law professor at Columbia University, told USA TODAY. "He would rather have her seat filled by someone of his choosing. That is not a lawful reason to fire her." Contributing: Bart Jansen This article originally appeared on USA TODAY:Will Trump's showdown with Fed's Lisa Cook end up at Supreme Court?