Rep. Keith Ellison (D-Minn.), the deputy chairman of the Democratic National Committee , became, all but officially, the lead proponent of single-payer health care in the House on Wednesday.

Ellisons House colleagues gave their unanimous consent for him to replace Rep. John Conyers (D-Mich.) as chief sponsor of H.R. 676, the Expanded and Improved Medicare for All Act . (Conyers is retiring at the end of his term under a cloud of sexual misconduct allegations .)

The move makes Ellison the most prominent House spokesman for once-marginal legislation that has become a rallying point for progressives across the country. The bill, which Conyers introduced for decades with little support, now enjoys the backing of a majority of the House Democratic Caucus. A companion bill introduced by Sen. Bernie Sanders (I-Vt.) has the backing of more than one-third of the Senate Democratic Caucus, including virtually every rumored 2020 presidential candidate.

Ellison, a longtime backer of H.R. 676, attributed the uptick in congressional support to lawmakers hearing from constituents desperate for a more effective health care system.

My motivation is just being in meetings, talking to people about their health care nightmare, and studying the array of options and coming up with this one as being the best one, Ellison told HuffPost.