"That position brings El-Sayed closer to his two rivals for the nomination, Rep. Haley Stevens, the most centrist candidate, and State Sen. Mallory McMorrow, who ideologically falls in between the other two.

Neither Stevens nor McMorrow supports Medicare for All. Instead, each has argued for creating a "public option" to compete against private insurance companies by allowing Americans of all ages to buy into Medicare.

Stevens believes a public option in the ACA is necessary "so that the insurance companies that are acting as a near-monopoly have competition," says Arik Wolk, her campaign communications director.

That approach has become the preferred alternative for many Democrats resisting single payer.

In Texas, Talarico promoted such a plan " what he called "Medicare for Y'all" " in his victory over Crockett. Several House candidates in competitive seats, such as Christina Bohannan in Iowa, have endorsed a public option, too."