Advocates for universal healthcare are calling for a boycott of the grocery chain Whole Foods over the views of its CEO, John Mackey. This week Mackey wrote an editorial in the Wall Street Journal criticizing President Obama’s plan to create a government-funded public healthcare option and dismissing the single-payer healthcare system of countries such as Canada and Britain. Mackey said he doesn’t believe in “an intrinsic right to health care, food or shelter,” which he said are best provided through “market exchanges.” On Thursday, the group Single Payer Action released a letter calling for a boycott of Whole Foods.