This article is from the archive of our partner National Journal

In the coming battle for progressive votes in Maryland's Senate race, Sen. Elizabeth Warren may play an outsized role in deciding a heated intraparty battle—regardless of whether the liberal icon chooses to endorse a candidate.

Rep. Elijah Cummings, who is weighing a Senate bid, has a relationship with Warren that precedes her 2012 election to the Senate—and has only deepened since she arrived in Washington. But many of the outside groups that have been Warren's strongest backers already are lining up behind Rep. Donna Edwards.

"It would not surprise me if she endorsed Elijah Cummings given their personal relationship," said a former Hill staffer with ties to Maryland politics. "She is not afraid to wade into things that she believes in." Even if she chooses not to endorse, he said, "I guarantee you she will be very overt in her compliments of Elijah Cummings."

Edwards' allies don't see that happening, citing the tricky political calculus involved. If Cummings runs, the race would pit one of Warren's closest Capitol Hill allies against a candidate with the backing of many of her strongest outside supporters. "When that happens, the easiest answer is, 'Hey, I'm gonna sit this out,'" said a progressive activist familiar with Maryland politics. "I wouldn't be surprised if that's what Sen. Warren decides to do in this particular race."

(RELATED: Elizabeth Warren's 11 Commandments of Progressivism)

Warren's office declined to comment on the Maryland primary matchup.

Another Maryland Senate contender, Rep. Chris Van Hollen, teamed up with Warren on a medical research bill this year. He's also put forth a tax plan that would limit tax breaks for CEOs and Wall Street traders—ideas very much in line with Warren's "fair share" mantra. Unlike Cummings and Edwards, however, Van Hollen is not a member of the Progressive Caucus—and voted against the group's budget proposal in the House.

Regardless of how involved Warren chooses to get in the race, her close ties to a possible candidate could make a difference. She's been friends with Cummings since 2011, when he defended her during a heated Oversight and Government Reform Committee hearing in which she testified, said a Cummings aide. Later that year, he feted Warren at a Baltimore town hall meeting as she pushed for the creation of the Consumer Financial Protection Bureau. "I can't get over my excitement," Cummings said at the time. "And I don't get too excited about many things."

Since Warren's ascension to Congress, the two have worked together on legislation, co-written op-eds, released joint letters, and launched the Middle Class Prosperity Project—which they kicked off with a series of forums to shed light on a "rigged" economic system. On Thursday, the pair held a student debt forum in Boston, Warren's home turf.

(RELATED: Sorry, Progressives: Elizabeth Warren Is Not Interested in Running for Democratic Leader)

"Senator Warren and I see eye-to-eye when it comes to helping the middle class and protecting consumers," Cummings said in a statement. "She has experienced a lot of hardship in her life, as have I, and I believe a lot of our pain fuels our passion to do our purpose."

Cummings may need that alliance to make a bid for the progressive mantle. Edwards has already sewn up early support from several national progressive groups, as well as EMILY's List. And the grassroots activist turned politician  also would be only the second African-American woman elected to the Senate, fulfilling a desire among many Democrats increase the party's diversity. (If Cummings won, he would be the third African-American male in the Senate, along with Democrat Cory Booker and Republican Tim Scott.)

In an interview, Edwards mentioned her own ties to Warren. "I have a history and a bit of a relationship with Sen. Warren too," she said. "I actually called on her expertise when I was first running for Congress in 2006, the election that I lost, when I wanted to understand what was happening in the banking and housing sector. "¦ If you look at the organizations that are supporting my candidacy, those are the same organizations that lined up behind Sen. Warren to propel her into the United States Senate."

Early on in the primary, there's been no indication Warren is ready to invest her political capital in a Democrat-on-Democrat fight (she's mostly used her icon status within the party to boost Democrats in tough general election contests, though she did endorse Kamala Harris in California's Senate race this year).

(RELATED: Elizabeth Warren Strikes Back Against New GOP Efforts to Weaken Dodd-Frank)

One progressive activist said the risk of backing Cummings over the views of liberal allies would not be worth the limited reward. "It would be really tough for Warren to buck some of these groups and get involved in a race like that," he said. "I don't believe that her endorsement in a Maryland Senate race is going to move a lot of voters."

Even if Warren does not get explicitly involved in the race, her presence—as a liberal standard-bearer and as a candidate's friend—will be felt. One Maryland Democratic strategist said Cummings' campaign would do well to play up those ties, but cautioned voters will want to hear about more than just Warren. "If they're smart, they would" mention the friendship, he said. "He has been working with her. She's popular in the state. "¦ Elizabeth Warren won't hurt in a Democratic primary, she most likely will help, but it's to the degree that she helps."

Cummings' office declined to weigh in on the Senate race, but discussed his friendship with Warren. "Cummings went to bat for her [in the hearing]," said one of his aides. "When she became a senator, they teamed up to do a lot of stuff together. Their priorities aligned on a lot of issues to help the middle class and protect consumers. "¦ They have a huge amount of respect for one another. Cummings is big into people who are passionate about they believe in."

The former Hill staffer with Maryland ties said the pairing goes deeper than policy issues. "There's a real genuine relationship," he said. "It's beyond 'my good friend from Massachusetts' and 'my good friend from Maryland.' It's Elijah and Elizabeth."

Meanwhile, Edwards' backers aren't waiting for Warren to tip her hand. "There's lots of progressive enthusiasm about Donna Edwards, even before Liz Warren decides she's going to weigh in," said the progressive activist with Maryland ties. "A lot of times Warren is important for showing early progressive support, but in this case there's no doubt where the base of the party is."

Others were even more forceful when asked about a potential Warren-Cummings alliance. "Donna Edwards has proven time and again that she's a bold progressive. She's not just a progressive ally—she's one of us," said Progressive Change Campaign Committee co-founder Stephanie Taylor. The PCCC was behind efforts to draft Warren to run for Senate in 2012 and did the same with Edwards this cycle. "In the Senate, she'll fight alongside Elizabeth Warren for an economic populist agenda that includes expanding Social Security benefits, making college more affordable, and holding Wall Street accountable."

Edwards believes she's earned such backing. "I'm a very progressive member of the Maryland delegation," she said. "If you take a look over the last several years of voting record and my work in the House, that would certainly be true. So it's not a surprise to me that a lot of the progressive organizations both in the state and around the country have supported me since I started running."

CORRECTION: The original version of this article incorrectly stated that the Progressive Change Campaign Committee had worked to draft Elizabeth Warren to run for president.

This article is from the archive of our partner National Journal.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.