A word of advice to Joe Biden after Sunday night’s debate: Call AOC.

In the two weeks that have seen Biden take back his position as the front-runner for the Democratic nomination, one voice has emerged as the progressive movement’s beacon of clarity. It’s not Bernie Sanders, who has chosen to remain in the race even though his chances going forward are objectively minuscule. The politician who has shown the most lucid understanding of the importance of Democratic unity in the face of Donald Trump is Sanders’ most obvious successor: Alexandria Ocasio-Cortez.

Often mistaken for a dogmatic ideologue, Ocasio-Cortez has astutely recast her role within Sanders’ orbit lately. She has urged the Democratic establishment to begin a conversation with younger Democrats. Rather than dwell on Sanders’ likely defeat, she has already set her sights on obtaining concessions from Biden. She has insisted progressives should “get real commitments on issues” for those demographics, like younger voters and Hispanics, who have overwhelmingly backed Sanders over Biden. While remaining a staunch defender of the progressive agenda and respecting her mentor’s decision to stay in the race at least through the next set of primaries, she has also put some subtle but increasingly relevant distance between Sanders’ quixotic pursuit of power and her own understanding of political mores. In recent days, for example, Ocasio-Cortez has made an eloquent call for inclusivity, touting tolerance and alliances as the path to victory, perhaps delicately hinting at the possible costs of a prolonged primary.

She is right. But even more importantly: By positioning herself as Sanders’ most persuasive surrogate with younger voters and Latinos—the progressive coalition’s current foundation— Ocasio-Cortez is poised to become the next great voice of the movement, Bernie Sanders’ true heir.

Before that, though, Ocasio-Cortez may have a crucial role to play in the presidential election. If, as she recently hinted, she fully supports Biden against Trump in the coming months, Ocasio-Cortez “could be the bridge between the Sanders and Biden campaign,” journalist Julio Varela told me. Varela sent me a link to one of Ocasio-Cortez’s recent Instagram Live chats, a 45-minute conversation with her more than 4 million followers in which she candidly shares her thoughts on Sanders’ string of defeats on March 10. “There no sugarcoating it,” she says. “Tonight’s a tough night electorally.” She seems slightly subdued but never angry, solemn, or somber. “It’s all about her deep appeal with young people and how she communicates with them,” Varela told me.

Come fall, Ocasio-Cortez’s instinctual understanding of younger Americans could be crucial for the Biden campaign, which has utterly failed to woo Democratic voters under 45. But bridging the generational divide is only part of what Ocasio-Cortez could bring to Biden. Perhaps more than with any other group, Ocasio-Cortez could play a crucial role in untangling Biden’s complicated relationship with Latino voters, laid bare at two particularly awkward moments during Sunday’s debate, when Biden carelessly referred to undocumented immigrants as “aliens” and then simply chose to ignore the very relevant question of why his message hadn’t resonated with Hispanics.

The truth is Biden indeed has a problem with the Latino electorate, especially younger voters. During the primaries, Biden’s Latino outreach has been as disappointing as his approach to black voters has been stellar. Rather than having the former vice president appeal to the community himself, the Biden campaign has relied on ineffective surrogates. The result has been dismal. Only 5 percent of young Latinos voted for Biden in California. The national picture is just as worrisome. As a proficient Spanish speaker who relates directly to the issues that have made progressive politics so relevant within the Latino community, Ocasio-Cortez could quickly upend that narrative. Granted, there isn’t much competition, but no Hispanic politician can match her charisma.

Ocasio-Cortez will need every ounce of her political acumen if she is to play a definitive role in bringing the Democratic Party’s progressive and moderate wings together after a fraught primary. As analyst Fernand Amandi told me, “the politics of personality” won’t be enough. “If she has national aspirations, but also wants to serve as a leader of the progressive moment in the years to come, she has to first figure out a way to bridge the gap between the 30–35 percent of hardcore Sanderista Democrats and the 65–70 percent of Biden Democrats who are not,” he said. Given the recent bitterness, it will not be an easy task. Still, if she manages to navigate the tightrope, Ocasio-Cortez could become Joe Biden’s most important ally, a future presidential contender in her own right and Bernie Sanders’ rightful heir as the voice of the progressive movement.

Not bad for a first term in Congress.