In a call to arms designed to further affirm his populist credentials and distinguish himself in a crowded primary field, Sen. Bernie Sanders (I-Vt.) committed on Wednesday to reject contributions of $200 or more from executives at the country’s pharmaceutical and health insurance companies, as well as the political action committees and lobbyists who represent them.

He then challenged his fellow contenders for the Democratic presidential nomination to pledge the same, dedicating a new webpage on his campaign site to the appeal.

“If we are going to break the stranglehold of corporate interests over the health care needs of the American people, we have got to confront a Washington culture that is corrupt ― that puts profits ahead of the needs of the American people,” he said toward the end of a speech about “Medicare for All” to an audience of cheering supporters in Washington. “And that is why today I am calling on every Democratic candidate in this election to join me in rejecting money from the insurance and drug companies. Reject that money!”

Sanders went on to suggest that those who did not reject that money should have to explain why the health care industry sees their candidacy as a “good investment.”

Sanders’ rivals in the Democratic primary are already in compliance with key elements of his pledge. All 24 Democratic candidates have rejected corporate PAC money of all kinds; 14 of them, including the leaders in the polls, have also renounced contributions from federal lobbyists.

HuffPost asked a number of the leading presidential campaigns whether they were prepared to reject contributions over $200 from executives in the pharmaceutical and health insurance industries. The campaign of Sen. Elizabeth Warren (D-Mass.), a fellow proponent of Medicare for All, said it would do so.

Sen. Cory Booker (D-N.J.) has rejected donations from top pharmaceutical company executives and corporate board chairs since 2017, though his campaign did not immediately say whether he would do the same for health insurance companies.

The campaign of Sen. Kamala Harris (D-Calif.) said she already rejects the contributions of pharmaceutical executives, but likewise did not specify whether she would bar health insurance executives from doing so as well.

Following publication of this article, it came to HuffPost’s attention that Harris had in fact received contributions over $200 from 14 people who appeared to be pharmaceutical executives. The Harris campaign told HuffPost it had already returned two of those donations and was in the process of returning 10 more. The campaign said it wasn’t sure whether the other two are from pharmaceutical executives and is seeking clarification.

The campaigns of former Vice President Joe Biden, Sen. Kirsten Gillibrand (D-N.Y.), South Bend, Indiana, Mayor Pete Buttigieg, and former Rep. Beto O’Rourke (D-Texas) did not immediately respond to requests for comment.

Steve Ricchetti, Biden’s campaign chairman, has lobbied for major pharmaceutical companies. Biden’s campaign has also received contributions from 15 pharmaceutical and health insurance company executives.