The skeptics were wrong. After a long period of speculation that only one of the progressive icons would run, Senators Bernie Sanders and Elizabeth Warren have both emerged as major players in the crowded Democratic primary. In a historically large field that includes a wealth of corporate-friendly moderates, the two senators have stood strong in their commitments to tackle growing economic inequality and the influence of money in politics, while the party establishment hesitates to antagonize capital. As Sanders and Warren prepare to debate next week, analysts everywhere are comparing the candidates’ political profiles—and missing the mark.

To many mainstream commentators, the firebrand senators’ simultaneous campaigns are an exercise in redundancy. And to many on the left, this situation provokes concerns that the progressive vote could split, allowing a moderate candidate to emerge from the field. We’ve seen countless think-pieces that contrast the two progressives’ policy priorities, bases of support, and public images. In the popular socialist magazine Jacobin, for instance, writer Shawn Gude compared the two senators’ differences to those between anti-war leader Eugene Debs, the standard-bearer of the Socialist Party of America, and the progressive lawyer Louis Brandeis, a former Supreme Court Justice nominated by Woodrow Wilson. “Warren’s political tradition is the left edge of middle-class liberalism; Sanders hails from America’s socialist tradition,” Gude argued. “Or, to put the distinction in more personal terms: Warren is Louis Brandeis, Sanders is Eugene Debs.”

Gude offers an interesting historical analogy to an argument made often by meticulous political observers: that Sanders’s immediate priorities are direct redistributionist policies, while Warren, reputed as a policy wonk, is most interested in systemic changes to the American market economy. Neither of these descriptions is without grains of truth, but this line of analysis feels scrupulous to a fault. Regardless of their ideological distinctions, neither candidate would be able to fully implement their transformative agenda without an agreeable Congress, which Warren and Sanders would surely admit. But the means to establishing a change-oriented Congress under progressive leadership relies on the core distinction between the two candidates—something Gude’s Jacobin piece, like various other takes, from The Washington Post to HuffPost, fails to identify.

The real difference between Sanders and Warren is actually quite simple: In the most basic of terms, Sanders sees himself as a progressive operating within the Democratic Party structure, while Warren sees herself as a Democrat who supports progressive ideals. As tautological as that may sound, the difference is rather meaningful from a left-wing perspective. For the most part, albeit with differences in the details, the two envision the same role for the American state: a government that protects the most vulnerable living among us by holding the rich accountable.

What differs in their visions is the ideal role of the Democratic Party. Sanders sees the party as an obstacle to meaningful progress, a box within which he is forced to work, given the catatonic nature of the American two-party system. Warren is surely frustrated by the friendliness of Democratic leadership toward Wall Street and multinational corporations—once lamenting that “Republicans and Democrats had locked arms to do the bidding of the big banks”—but she is fundamentally a party loyalist. In her view, the Democratic Party is, if not good, an acceptable vehicle for political change in need only of tweaking rather than a complete makeover.

Sanders’s team, by contrast, established Our Revolution, a social-democratic PAC that aims to push the Democratic Party leftward. While the PAC has been criticized in outlets like Politico, which alleges disorganization and inefficacy on Our Revolution’s part in the years since its 2016 launch, it has been active in its support for hundreds of candidates across the country at national, state, and local levels. For his part, Sanders has directly invested considerable resources in support of insurgent candidates like Michigan’s Abdul El-Sayed and Florida’s Andrew Gillum, and Sanders’s allies have nurtured the growth of groups like the Justice Democrats, which helped elect the members of the Squad to Congress last year.

Win or lose, the mere specter of Sanders involving himself in a contested primary is enough to make party moderates uncomfortable. Even before Our Revolution and Justice Democrats candidate Alexandria Ocasio-Cortez’s congressional campaign proved threatening to incumbent Joe Crowley, her entrance into the race in 2017 was enough to push Crowley left, causing him to sign on in support of Medicare for All. Warren, on the other hand, has taken a radically different path, choosing to play it safe in virtually every major contested primary, a political calculation that stands in stark contrast to her fearsome advocacy for issues such as student-debt cancellation and trustbusting.

The only notable endorsements by Warren in the primaries for the 2018 midterms were seen in California, where she supported her protégé Katie Porter’s successful bid for Congress, and in Ohio, where she backed longtime collaborator Richard Cordray’s unsuccessful gubernatorial run. (Cordray beat Our Revolution candidate Dennis Kucinich in the primary, then lost to Republican Mike DeWine in the general election.) Warren did not support El-Sayed or Gillum in their primaries and notably chose not to endorse Sanders ally and civil rights leader Ben Jealous until after he won the primary in his bid for governor of Maryland, even as he garnered support from major players in the Democratic establishment such as Senators Kamala Harris and Cory Booker, both of whom are now running for president.

When Warren has used her national stature to wade into electoral politics, it has almost invariably been to boost the fundraising efforts of conventional Democrats backed by the party establishment, even when their stated platforms are at odds with hers. In 2016 she made national headlines for her efforts to elect then-rising star Jason Kander when he mounted a surprisingly competitive race for Senate in deep-red Missouri. After the centrist Marine Corps veteran Amy McGrath won a 2018 Kentucky congressional primary on largely nonideological lines, Warren assisted McGrath via the senator’s enviable email list.

Supporting centrist candidates running in tough territory is perfectly reasonable. After El-Sayed’s loss, Sanders stumped for establishment-backed Democratic nominee Gretchen Whitmer’s Michigan gubernatorial bid and made a stop in Nevada to support moderate Democrat Jacky Rosen’s campaign for Senate, both of which succeeded in November. But it is evident from Warren’s forays into electoral politics that her political imagination begins and ends with getting more Democrats elected to high office, regardless of their quality.

There’s only so much a Democratic majority could accomplish as long as the party’s institutions are ridden with hedge fund managers, defense contractors, pharmaceutical lobbyists, and other actors whose interests are in diametric opposition to the progressive reforms that Sanders and Warren champion. In the two years since Trump’s inauguration, the leadership of the Democratic Party has invested far more time and energy into curbing potential opposition from its left than it has to resisting the total acquisition of America’s political institutions by the far right. Sanders intimately understands this. Warren, irrespective of her personal beliefs, does not operate as if she does, and that could prove a major impediment to achieving her policy goals.

For a half-century, internal Democratic debate has been set on the terms of the party’s right wing, and the result has been the total transformation of the party that brought the United States the New Deal into a staid, hollow institution more interested in self-preservation than in improving the lives of its voters. This makes the vocal presence of both progressive lions in the presidential race more than welcome, especially at such an early point in the primary cycle. But in the coming months, progressives are going to have to make their choice. Ultimately, it is Sanders, not Warren, who foregrounds his values over party loyalty, making him the more effective general-election candidate—and president.

Correction: A previous version of this article incorrectly stated Amy McGrath’s military service background. She is a retired US Marine Corps lieutenant colonel, not an Air Force veteran.