After years of signs that the American parties were institutionally weak and vulnerable to takeover, Democratic Party elites coalesced to quickly replace their presidential candidate. But a longer historical sweep suggests it will not be a quick return to parties’ traditional roles. Daniel Schlozman and Sam Rosenfeld find that Democrats and Republicans have become hollow shells, unrooted in civic organizations, with Republicans captured by extremism and Democrats ineffectual. Their weaknesses, they say, are the source of our political discontent.