Meanwhile, for more than a century — in churches and temples, in union halls and neighborhood centers, in the streets and at the ballot box — progressives have moved the country forward. Progressives brought us minimum wage and Social Security in the 1930s, civil rights and Medicare in the 1960s, and health care and Wall Street reform in 2010.

Opponents of these accomplishments — some of society’s most privileged and well-entrenched interest groups — have not changed much. The John Birch Society of 1965 has bequeathed its fervor and extremism to the Tea Party of 2010.