Elizabeth Warren has to worry about more than Cherokees tomorrow. The Harvard law school professor and sainted champion of the financially reformed middle class will likely face a primary challenger after the state’s Democratic Party Convention on Saturday. That challenger, Marisa Defranco, is a less hawkish immigration lawyer and self-described wisenheimer in need of only 15% of the Convention vote to force a primary–an easily attainable margin, the New York Times reported Sunday.

MA political guru Professor Peter Ubertaccio deems a competition good for the progressive cause:

Progressivism began as more than just a policy regime designed to ameliorate the social and economic inequalities that existed in turn of the 20th century America.  It was also an anti-party movement designed to strike at the power party bosses had at their disposal to dispense nominations, control patronage, and obstruct national regulation over state and local affairs.  Primary elections emerged as one of the most powerful tools used by progressives to make parties answerable to the party faithful.  Ordinary voters gained the right to choose party nominees and that right has been fairly sacrosanct ever since.

But Defranco may make some Democrats nervous because she does not partake of the meliorist progressive tradition: her website announces support for single-payer health care, massive “green jobs” subsidies, opposition to free trade, and outrage over student debt. Defranco is more William Jennings Bryan than Bob Lafollette. And while some of her “issues” prose is slightly awkard–on women: “I do not reduce us simply to our uteri”–her position on Iranian intervention unequivocally guts the usual bipartisan drivel: “We. Are. Not. Going. To. War. With. Iran.”  She loathes the military industrial complex, and urges total withdrawal from Afghanistan and Iraq.

Defranco’s skepticism of bellicosity puts her at odds with the progressive Warren, and the largely neoconservative incumbent Sen. Scott Brown. The less hawkish stance might connect with Bay State voters, who were less-than-thrilled with the aggressive Bush years. And Defranco’s antiwar standard could offer a legitimate alternative to the leading candidates, who show little interest in discussing actual issues.

If Defranco’s authentic bent and underdog status catch on, they could cause trouble for the state’s Democratic machine so effectively derided by Brown in his 2010 victory over Martha Coakley. Early tension has already surfaced. Governor Deval Patrick, known for his close ties to President Obama, has endorsed Warren, inducing an uncomfortable skepticism in Boston Mayor Thomas Mennino, who told the Boston Herald, “This is not the time or the place for endorsements right now.” Warren’s establishment status comes with a large fundraising advantage–according to the Associated Press, her cup overflows with $15.8 million snagged through March 31 against the paltry $40,000 in Defranco’s clinging coffers–but may tar her as an elitist. And with the grassroots no longer in love with Brown, it’s not difficult to imagine Defranco emerging as a sponge for populist discontent.

A Defranco primary victory could put President Obama in a precarious position, with  Brown ideologically closer to the president than the Democrat in a crucial Senate race. Defranco is currently far behind Warren in the polls, and winning the nomination requires far more than 15% of a Convention vote. The race may matter more for what it reveals about the president’s decidedly mixed approach to foreign policy: his politicized machinations may counter some Republican attacks, but his own party could buckle.

Maybe it’s not Elizabeth Warren’s seat, either.