WASHINGTON — Tina Tchen, former chief of staff to former first lady Michelle Obama, stepped up her fight on Wednesday to quash a subpoena digging for information about her role in Jussie Smollett’s alleged fake hate crime case.

Lawyers for Tchen, an attorney who heads the Chicago office of Buckley LLP, were filing a motion to quash the subpoena in Cook County Circuit Court, the latest twist in a case that started out with Smollett, an openly gay African American actor who starred in “Empire,” initially claiming that he was the victim of a racially motivated and homophobic attack.

Smollett ended up being charged with 16 counts of disorderly conduct for allegedly staging the attack but those charges were abruptly dropped. The actor forfeited the $10,000 bond he posted and never admitted any wrongdoing.

Tchen is resisting a subpoena that is an outgrowth of a civil case filed by retired former state of Illinois Appeals Court Judge Sheila O’Brien, who has filed multiple legal bids related to the Smollett case and the handling of it by Cook County State’s Attorney Kim Foxx.

Why O’Brien is so actively interested in the case has not yet become clear.

O’Brien jumped in the case in April, asking a judge to appoint a special prosecutor to investigate Foxx.

The brief filed to support Tchen’s motion to quash argues O’Brien has no business asking for a special prosecutor or any information because she “holds no position or authority within the Illinois justice system. Yet, she claims the power not only to institute this proceeding, but to compel Ms. Tchen to participate by appearing in court to testify and produce documents, and submitting to an ‘evidence deposition.’”

Moreover, the brief argues, O’Brien “has no legal right to make her demands of Ms. Tchen and, even if Petitioner did, those demands are inconsistent with the applicable rules of discovery and not supported by any showing of good cause.”

Tchen’s effort on behalf of the Smollett family has thrown a national spotlight on whether she crossed a line.

Because of her connection to former President Barack Obama and Mrs. Obama, Tchen’s involvement in the Smollett probe has provided fodder for right-wing outlets and conspiracy minded commentators on social media.

Tchen is linked to the Obamas for life. On Thursday, Tchen will be in Grand Rapids, Michigan, to participate in a White House Historical Association panel on “Inside the White House: Behind the Scenes of the First Lady’s Office.”

Given her background on gender and race issues and internal workplace investigations, it’s an irony of sorts that the first major national controversy Tchen has ever faced has to do with her handling of hate crime allegations involving an African American gay man.

Tchen, in the Obama White House and now in her legal practice and other activities deals extensively with harassment, sexual assault, sexual inequity and related issues.

In the Obama administration, she was the executive director of the White House Council on Women and Girls as well as Mrs. Obama’s chief of staff. Tchen led the White House Task Force to Protect Students from Sexual Assault.

Since the spawning of the MeToo! movement, Tchen has become a sought after lawyer dealing with conduct issues.

She is the co-founder of the Time’s Up Legal Defense Fund — helping women who have been harassed in the workplace — and was recently tapped to lead a review of the working conditions at the Southern Poverty Law Center. She also chairs the National Academy of Recording Arts & Sciences Task Force on Diversity and Inclusion.

Tchen gave her side in a March statement: “I know members of the Smollett family based on prior work together. Shortly after Mr. Smollett reported he was attacked, as a family friend, I contacted Cook County State’s Attorney Kim Foxx, who I also know from prior work together. My sole activity was to put the chief prosecutor in the case in touch with an alleged victim’s family who had concerns about how the investigation was being characterized in public.”

The subpoena demands Tchen produce “any and all documents, notes, phone records, texts, tape recordings made or received at any time, concerning your conversations with Kim Foxx in re Jussie Smollett.”

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Benjamin B. Klubes, managing partner of Buckley LLP said in a statement, “We filed a motion today asking the court not to allow Sheila O’Brien to collect documents and take testimony from Tina Tchen in connection with Ms. O’Brien’s petition to appoint a special prosecutor to investigate the Jussie Smollett matter.

“We filed our motion because there is no basis for the appointment of a special prosecutor, and the court already has ruled that similar efforts to collect documents and take testimony from the State’s Attorney’s Office were improper.

“Ms. Tchen is cooperating fully with an inquiry by the Cook County Office of the Independent Inspector General, which is the government entity with an appropriate oversight role in the matter.”

Tchen’s reputation took a hit with recent stories asserting she was dodging efforts to serve the subpoena. Klubes also said in his statement, “While Ms. O’Brien apparently circulated to the media an incorrect claim that Ms. Tchen had evaded service, we contacted her directly upon learning of the subpoena from the media and accepted service on behalf of Ms. Tchen the same day the process server came to our building.”

O’Brien has also issued a subpoena for Foxx top deputy Joseph Magats, a move that was quashed on procedural grounds by Cook County Circuit Court Judge Michael Toomin earlier this month.