News that Bernie Sanders had a heart procedure for a blocked artery is a “serious setback” for his presidential campaign, says Carleton College political analyst Steven Schier:

“His main rival for the left wing of the party is Elizabeth Warren. This will further boost her candidacy, which has been rising in any event before this.”

Schier says Sanders’ health problem also brings up the age issue generally in the campaign and might give some Democrats pause about nominating any older candidate for president. He says the obvious problem would be for Joe Biden, who’s 76.