CREDIT: Matt Mahurin

The late Democratic Senator George S. McGovern and today’s Republican Tea Party activists might not have a great deal to say to each other — they both represented their party’s extremes. For that very reason, however they have one thing in common: Their rise to prominence defied the wishes of their respective party’s establishment.

Forced to fling open the doors to their smoke-filled back rooms, party leaders no longer possess their once-vaunted power over the careers of would-be presidents, governors, county legislators, and even, yes, the occasional dog-catcher.

Into this political breach marches the U.S. Chamber of Commerce, the lobbying arm of big business, which recently announced its intention to campaign aggressively for mainstream, Republican incumbents faced with challenges from Tea Party members. The Chamber is hardly the only private organization looking to impose discipline and order over post-boss politics. Other groups are also seeking to do this, including Friends for an American Majority, a group of wealthy donors led by Paul Singer, a New York billionaire, and the American Opportunity Alliance.

This Republican chaos should look familiar to Democrats. They’ve been there, done that. Their command-and-control system broke apart in the 1960s, leading to McGovern’s 1972 nomination.

The Democratic Party’s remaining bosses vehemently opposed McGovern. They saw him as a certain loser, and, more to the point, an unreliable outsider. But thanks to reforms that made the nominating process more democratic, there was nothing the bosses could do as alienated young people flocked to McGovern’s insurgent candidacy. The bosses were right, however. McGovern ultimately suffered an historic loss to incumbent President Richard M. Nixon.