In the past few weeks, President Donald Trump’s administration has directed attention toward Democratic officials concerning accusations of mortgage fraud, opening a new chapter in its challenge to critics.

The most recent development occurred on Wednesday when Trump, who has frequently criticized the Federal Reserve’s interest rate policies, used his Truth Social platform to demand Federal Reserve Governor Lisa Cook “must resign, now!!!”

Trump’s statement followed allegations made by William Pulte, director of the Federal Housing Finance Agency. In a letter to Attorney General Pam Bondi, Pulte accused Cook, who was appointed by President Joe Biden, of “falsifying bank documents and property records to obtain more favorable loan terms, possibly engaging in mortgage fraud.” The letter asserted that Cook misrepresented her residency for her properties in Ann Arbor, Michigan, and Atlanta.

This move comes after earlier actions targeting Sen. Adam Schiff, D-Calif., a prominent figure in Trump’s impeachments, and New York Attorney General Letitia James, who successfully litigated against Trump and his company over allegedly fraudulent financial misrepresentations. These misrepresentations, according to her office, enabled Trump to obtain bank loans and insurance policies on favorable terms that he would not otherwise access. A judge awarded more than $300 million in this case to James’ office, with the amount subsequently increasing to over $500 million with interest. Trump, who is appealing the judgment, has described the case as “a fraud on me.”

Earlier this month, NBC News reported that Bondi appointed Ed Martin, a conservative activist and former interim U.S. attorney for Washington, D.C., to serve as a “special attorney” to investigate the mortgage fraud allegations against Schiff and James. A senior law enforcement official informed NBC News that a grand jury in Virginia is expected to examine the allegations against James, while the Schiff allegations will be reviewed by a grand jury in Maryland. Trump has called for both of these officials to face prosecution based on the allegations.

Schiff, James, and now Cook have all firmly denied any misconduct. The White House deferred questions to the Federal Housing Finance Agency, which provided no comment.

Making an allegation of mortgage fraud has long been a common tactic in opposition research on political campaigns.

A Republican campaign veteran told NBC News that searching for inconsistencies in where candidates declare their “primary” residences is among the first tasks for opposition researchers. It is an issue relevant to elected officials who split their time between their home states and Washington. This person said it is a frequent issue in campaigns on both sides, and the penalty tends to be a fine, not jail time.

Last year, Sen. Angela Alsobrooks, D-Md., then a candidate for office, faced a $47,000 bill in Washington, D.C., after it was discovered she wrongly received property tax credits she improperly claimed on a home she had rented out.

“It looks sloppy,” this person said. “But I don’t think we’ve ever had anyone screw up their life on this. It just looked bad.”

Now, the Trump administration is giving such allegations against Democrats special attention.

At the same time, The Associated Press reported that Texas Attorney General Ken Paxton, a Trump ally who is running for the Senate, and his wife, Angela, made inaccurate statements on mortgage applications claiming that three separate properties were each their primary residence. The Trump administration has not said whether Paxton is under similar investigation.

In a letter to Martin on Monday, James’ lawyer, Abbe Lowell, pointed out the potential inconsistency in enforcement actions.

“Notably, absent from your mandate is Kenneth Paxton (Republican Attorney General of Texas). Given that the same news reports raising questions about Ms. James and Mr. Schiff have reported that, somehow, Mr. Paxton has three different properties that he claims to be his ‘primary residence,’ it seems to indicate your title ought really be, ‘Special Assistant for Mortgage Fraud [Alleged Against Democrats verse to President Trump],’” he wrote.

Pulte said in an interview with CNBC on Wednesday that the administration’s probes of the allegations of mortgage fraud were free from political considerations.

“We will look at any allegation of mortgage fraud,” he said. “And we do not care whether you’re a Republican, a Democrat. We do not care whether you’re wealthy. We don’t care whether you’re a prosecutor. We don’t care whether you’re a Fed governor, if you commit mortgage fraud and you present an existential threat to the Federal Home Loan Banks, Fannie or Freddie, we are going to prosecute it, period.”

Cook, the first Black woman to serve on the Fed’s Board of Governors, said in a statement Wednesday that she learned from news reports that Pulte had made a criminal referral against her “based on a mortgage application from four years ago, before I joined the Federal Reserve.”

“I have no intention of being bullied to step down from my position because of some questions raised in a tweet,” she said. “I do intend to take any questions about my financial history seriously as a member of the Federal Reserve and so I am gathering the accurate information to answer any legitimate questions and provide the facts.”

Later Wednesday, Sen. Elizabeth Warren, D-Mass., said the episode amounted to the latest example of the Trump administration’s trying to pressure the Federal Reserve.

“I’ve long been an advocate for holding Fed officials accountable,” Warren, the ranking member of the Senate Banking Committee, said in a statement. “But anyone can see that for months now, President Trump has been scrambling for a pretext to intimidate or fire Chair Powell and Members of the Federal Reserve Board while blaming anyone but himself for how his failed economic policies are hurting Americans. The President and his ministration should not weaponize the Federal government to illegally fire independent Fed Board members.”