Is the American Party System About to Crack Up?

Here's Danielle Allen, at the Nation, "Communications Breakdown":

In 1999, the libertarian party helped transform American politics by launching a campaign that ultimately sent hundreds of thousands of e-mails to the Federal Deposit Insurance Corporation to protest its proposed “know your customer” banking regulations. The FDIC withdrew the rules, and the era of digital politics was born. Roughly a decade later, social media propelled “birtherism” to the forefront of the national conversation, reinstating nativism as an active ideology in the United States. In 2009 came the Tea Party movement, followed by Occupy Wall Street in 2011, both of which drew on new online organizing mechanisms to build solidarity networks around a particular analysis of social reality. The question for students of American politics now is whether these changes can drive a fundamental realignment of our political parties.

Transformations in communications technology have made it more possible than ever before for dissenters from the Democratic and Republican parties to find one another and to form sizable communities of interest. The result is lowered barriers to entry for the work of political organization, with consequences announced daily in headlines about the 2016 presidential campaign. Insurgent candidates in both parties have drawn on the organizational power that has developed over the past decade within ideologically defined communities: Donald Trump has summoned the anger and xenophobia of the birthers, Bernie Sanders has channeled Occupy’s critique of rampant inequality, and Ted Cruz has marshaled the forces of the Tea Party universe. By attaching other groups of voters to their original, more ideologically concentrated constituencies, these candidates have achieved greater success in their respective primary campaigns than anyone thought possible just one year ago.

Regardless of whether they succeed in taking over their parties, these new coalitions have the potential to remake American politics if either the insurgents or the party faithful are driven to seek refuge in existing third parties or to create entirely new ones. For the 2016 campaign at least, that latter possibility is already foreclosed, so a takeover (hostile or otherwise) of a third party seems more likely—both the Libertarian Party and the Green Party can place candidates on the ballot in a significant number of states. Even so, our first-past-the-post electoral system makes it very hard for third parties to challenge the top two. Barring the emergence of new habits of collaboration and alliance formation among small parties, only a fundamental change to our system of voting—the introduction of proportional representation, for example—would allow for a more fluid political system to develop.

 Speculating on what the future holds for America’s political alignment requires thinking through a complex array of factors: voting rules, political egos, the time horizons of charismatic leaders, questions of succession, the intensity of various ideological commitments, and a famously mutable public opinion. What we are most likely to see is more of the new normal: incredibly bitter fights among plurality-sized groups for total—if temporary—control of one of the major parties. Will this also worsen gridlock at the national level, thereby exacerbating the intensity of those intraparty battles and further destabilizing our political system overall? If these dynamics play out simultaneously in both parties, the most unified side will triumph.

There's more, FWIW, from Rick Perlstein and Daniel Schlozman at the link.