Feeble Gatekeepers: Factional Insurgency and the Toppling of the Grand Old Party.

This paper explains the radicalization of partisanship in the US emerging from the increasing influence of extreme activists and their followers against debilitated party structures. The dynamic has been particularly acute in the Republican Party, with its base of "grievance" voters seeking to over-throw the establishment. In the Republican Party, a large faction believes it faces an existential threat to their conservative and white racial identities. For decades, traditional party leaders have become less capable of managing these tensions as a new wave of media savvy leaders (initiated by Newt Gingrich) stoked political fear and anger, rooted in religious and racial attitudes. A problem for the Republican Party is that traditional leadership (both elected and organizational) have lost gatekeeping power to keep out the most illiberal elements in the party. In fact, the illiberal elements now control many party organizations at the grassroots. The loss of gatekeeping power has its roots in a century-long project of Progressives at the turn of the 20th century, trying to all but eliminate transactional political parties. In more recent decades, campaign finance reforms intended to reduce money in politics ended up incentivizing non-transparent methods to finance campaigns, as well as judicial challenges to the law, which led to the breakdown of formal regulations. Today, Super PACs funded by radical libertarian billionaires (and extreme and wealthy liberals on the left) now dominate the system causing greater partisan polarization. The extremism is not mitigated by the rise of small donors who tend to favor populists like Donald Trump and ideological standard-bearers like Bernie Sanders. The most profound effect of these changes has been on the Republican Party because its constituencies are in decline relative to groups supporting Democrats. Under these seemingly existential conditions, the Republican Party has been overtaken by insurgents -- mostly ethno-nationalists. Trump took over a party that was ripe for collapse. Its traditional elites - both elected and party officers -- lacked the capacity to hold norm-breaking members accountable. Paradoxically, the weakening of the GOP and its growing illiberalism owes much to the party-weakening reforms pushed by liberal Democrats for more than a century.