Sanders at a rally in Tucson, Ariz. (Rick Scuteri / AP)

This post originally ran on Robert Reich’s website.

New York Times columnist Paul Krugman Friday warned Bernie supporters that change doesn’t happen with “transformative rhetoric” but with “political pragmatism” – “accepting half loaves as being better than none.” He writes that it’s dangerous to prefer “happy dreams (by which he means Bernie) to hard thinking about means and ends (meaning Hillary).”

Krugman doesn’t get it. I’ve been in and around Washington for almost fifty years, including a stint in the cabinet, and I’ve learned that real change happens only when a substantial share of the American public is mobilized, organized, energized, and determined to make it happen.

Political “pragmatism” may require accepting “half loaves” – but the full loaf has to be large and bold enough in the first place to make the half loaf meaningful. That’s why the movement must aim high – toward a single-payer universal health, free public higher education, and busting up the biggest banks, for example.

But not even a half loaf is possible unless or until we wrest back power from the executives of large corporations, Wall Street bankers, and billionaires who now control the whole bakery. Which means getting big money out of politics and severing the link between wealth and political power – the central goal of the movement Bernie is advancing.