President Donald Trump' s push to oust Rep. Ilhan Omar amid allegations of immigration fraud could trigger a constitutional fight, with legal experts telling Fox News Digital that a landmark Supreme Court case involving another entrenched Democrat may not stand in Republicans’ way.

Federal investigators are examining whether the Minneapolis Democrat improperly obtained U.S. citizenship through allegedly fraudulent immigration paperwork involving her late father. Omar has denied wrongdoing, and no finding that she lacks U.S. citizenship has been established.

Experts said Omar may not have the protections established in the landmark case involving House chairman Adam Clayton Powell Jr., D-N.Y., in which the Supreme Court blocked an effort to exclude him from Congress. Powell faced allegations of misusing congressional funds and improperly paying his wife from the congressional payroll. Despite his reelection, the House voted to exclude him in 1967, but the Supreme Court later ruled that Congress could not refuse to seat a duly elected member who satisfied the Constitution's qualifications.

The first potential route for Republicans would be to challenge whether Omar meets the Constitution's citizenship requirement. Former Deputy Assistant Attorney General John Yoo and constitutional scholar Cully Stimson told Fox News Digital that the Powell ruling does not prevent Congress from enforcing constitutional qualifications.

"Powell essentially means that Congress cannot add on to the minimum qualifications set out in the Constitution," Yoo said. "[S]ince citizenship is set out in the text of the Constitution as a qualification, it clearly can be enforced by Congress. Powell in-fact would support a congressional decision to oust Congresswoman Omar if she was in fact not a citizen."

Stimson argued that citizenship itself is not a legal gray area. "The Powell v. McCormack decision did not involve expulsion. It actually was to judge qualifications. That's a subtle but important difference," he said.

Stimson envisioned a January showdown if federal authorities presented evidence challenging Omar's citizenship before the new Congress convenes and House Republicans attempted to prevent her from being seated. Such a move would likely face a legal challenge from Omar, he said, raising questions about whether Congress could act before her citizenship status was resolved.

The Constitution requires House members to be at least 25 years old, have been U.S. citizens for seven years and inhabit the states they represent when elected.

Stimson argued that even if alleged immigration irregularities originated with Omar's father, Nur Omar Mohamed, the central question would be whether she legally acquired citizenship, regardless of whether she knowingly participated in wrongdoing. "It's like you're either pregnant or you're not," he said. "You’re either wet or dry — You're a citizen or you are not a citizen."

In multiple public comments, Trump has urged Omar’s resignation or expulsion, specifically citing reports that she used a pseudonym when she was sworn into office and that she "married her brother." "Let’s get her the Hell out of there," he said Monday in Alcorn County, Mississippi. Fox News Digital reached out to Omar for comment.

A second route would involve seating Omar and then pursuing expulsion for misconduct, a separate constitutional power requiring a two-thirds House vote. Unlike exclusion for failing to meet constitutional qualifications, expulsion is a disciplinary action that was not at issue in the Supreme Court's Powell ruling.

At least one House Republican has already threatened to pursue that option. Rep. Randy Fine, R-Fla., said Friday that if Omar is found to not be a citizen, "I absolutely will demand expulsion immediately."

Omar faces a separate investigation into her financial disclosures, which U.S. Attorney Jeanine Pirro previously confirmed to Fox News. The inquiry follows scrutiny of businesses tied to her current husband, Timothy Mynett, whose reported valuations reached as high as $30 million before Omar amended the filings, citing accounting errors. No financial wrongdoing has yet been established.

Stimson pointed to the 2023 expulsion of former Rep. George Santos, R-N.Y., as an example of the House exercising its disciplinary authority over misconduct that began before a member took office.

Former House counsel Michael Stern wrote in an examination of the Constitution’s expulsion clause that while Santos’ alleged misconduct largely preceded his term, House investigators found that his misrepresentations continued while he was in office.

"Thus, acts committed before a member’s first election may constitute disorderly behavior subject to congressional discipline, at least if the misconduct relates to the election and particularly if it involves deceiving the electorate," Stern wrote.

Stimson said Omar’s case is largely "uncharted waters," but the Santos case could still be instructive. "I think the argument would be, well, her misrepresentations continued during the time in Congress, they would pull a Santos and use the same logic that they used," he said.

Any federal determination challenging Omar's citizenship could trigger a legal battle over whether she meets the constitutional requirements for office and what recourse she would have to contest such a finding, Stimson said.

"The hard part for her is ‘how do you prove a negative’," Stimson said, adding that placing blame on her father wouldn’t stand up in court because people cannot legally benefit from others’ criminal acts. "It’s a harsh world, but it’s a binary situation." also produce a separate fight over the evidence and legal procedures required to establish whether she meets the Constitution's qualifications.