Fresh off a victory against Trumpcare, health care activists are now looking hopefully towards the future. Already there has been significant progress: within the Democratic Party “Medicare for All” has now achieved a level of support and enthusiasm unprecedented in recent memory.

Yet even as a broad spectrum of progressives coalesces around the cause, others are warning that we should be pressing on the brakes, not the throttle. Joshua Holland penned a piece in the Nation making this case just last week, and Paul Krugman made many similar points in his New York Times column on Monday.

Both argue that single payer should not be a “litmus test” for progressive candidates. They’re sorely mistaken.