WASHINGTON — With the March 17 Illinois Democratic primary looming, Mayor Lori Lightfoot in a tweet said the anti-abortion Rep. Dan Lipinski should be defeated, but she did not endorse either of his two main challengers who support abortion rights, Marie Newman and Rush Darwish.

In a tweet posted late Saturday night on Lightfoot’s political account, the mayor said, “I support a big tent but there’s no room under the flaps for anyone who is actively seeking to deny women control over our bodies. Time to leave @danlipinski.”

I support a big tent but there's no room under the flaps for anyone who is actively seeking to deny women control over our bodies. Time to leave @danlipinski. https://t.co/DvZaSP8jXx — Lori Lightfoot (@LightfootForChi) January 5, 2020

Lightfoot did provide a clue that she was at least leaning toward Newman. She posted her tweet over a Jan. 2 tweet from Daily Kos, a progressive outlet supporting Newman that seeks contributions to her campaign: “Democrat” Dan Lipinski just co-signed this legal brief asking the Supreme Court to revisit Roe v. Wade “and, if appropriate, overrule” it ... Donate to his progressive challenger, Marie Newman.”

Whether Lightfoot – a progressive who supports abortion rights – will do more than send a tweet to defeat Lipinski is not known. Lightfoot political director Dave Mellet told the Sun-Times on Sunday, “The mayor is still making decisions in the 2020 primary, but she felt compelled to speak out and defend the rights of women.”

The Lipinski campaign declined to comment on Lightfoot’s remarks.

Lipinski’s opposition to abortion is well known; he is one of a dwindling number of Democrats in Congress who’s anti-abortion.

What put this issue on the front burner - and triggered Lightfoot jumping into the primary - was Lipinski’s decision to sign onto a friend of the court brief filed in a Louisiana case seeking to overturn the landmark Roe v. Wade, which legalized abortion in 1973 nationwide.

The brief was signed by 207 members of Congress, almost all Republican. Lipinski was under no obligation to add his name. Signing the brief sparked an outcry from abortion-rights groups and voters while at the same time served to remind his anti-abortion supporters - part of his political base - of his strong stand.

Lipinski narrowly won a one-on-one battle with Newman in 2018 - 51.1 % to 48.9% - with the help of the anti-abortion vote.

An internal campaign document obtained by the Sun-Times in November revealed that Lipinski’s proposed March strategy included emphasizing his opposition to abortion in pitching Republicans and Catholics, but not for outreach to other women, millennials, teachers, independents, union members and nurses.

Facing two abortion rights challengers in 2020 may only split the Lipinski opposition and make it easier for him to win another term in the heavily Democratic district.

In May, the major abortion rights groups - EMILY’s List, NARAL Pro-Choice America and the Planned Parenthood Action Fund - endorsed Newman.

Lipinski won in 2018 in part because of the efforts of the anti-abortion Susan B. Anthony List which in the final days of the primary led an independent grassroots get-out-the-vote drive for him.

The 207 signers of the amicus brief included 39 senators and 168 members of the House of Representatives, representing 38 states. All five Illinois Republicans in the House signed - Darin LaHood, John Shimkus, Rodney Davis, Adam Kinzinger and Mike Bost. Lipinski was one of two Democrats on the brief.

The brief stated, “Amici Members have a special interest in the correct interpretation, application, and enforcement of health and safety standards for elective abortion enacted by the People of the States they represent.”

Newman, of La Grange, the front runner who has a string of endorsements from local and national figures, and Darwish, of Palos Hills, both blasted Lipinski, of Western Springs, for signing the brief in Jan. 2 statements.

Newman said, “Congressman Lipinski’s decision to sign this amicus brief asking the Supreme Court to reconsider Roe v. Wade is further proof of his willingness to pursue a distorted personal agenda and extreme views at the expense of his constituents’ health and best interests.

“My opponent does not trust women and he is not fit to represent us. Congressman Lipinski refuses to stand up for the values of our community and it is time that our district has real leadership.

“Congressman Dan Lipinski, co-chair of the Congressional Pro-Life Caucus, has co-sponsored 54 bills attacking abortion rights, including bills sponsored by Mike Pence, Steve King and Todd Akin. He co-sponsored legislation to require invasive ultrasounds before women receive an abortion, and he voted against a measure to create an exemption to an abortion ban for when the life of the mother was at risk.

“Donald Trump personally thanked Lipinski for his work supporting the movement to take away a woman’s right to choose at an anti-abortion dinner in 2018.”

Darwish said, “Dan Lipinski yet again makes clear that he’s not interested in standing up for women’s rights. The 3rd District needs a Representative who will stand up for women’s rights and human rights broadly.

“Anyone who believes that people should be able to choose what they do with their own bodies and their own healthcare will see this for what it is: a bigoted and cynical ploy for Lipinski to virtue signal conservatives to vote for him in the primary. He cares more about his own election than about his constituents or their rights.”

Planned Parenthood Illinois’ Brigid Leahy, senior director of public policy, said in a statement, “This case could decide the future of abortion access in this country and we will not silently stand by and let Congressman Lipinski pledge his support for taking away Illinois women’s right to a safe and legal abortion.”

The district takes in parts of Chicago’s Southwest Side plus south and west suburban turf, sweeping in precincts in the following city wards: 11, 12, 13, 14, 15, 16, 18, 19, 20, 22 and 23.