The political party system in the United States has periodically undergone major realignments at various critical junctures in the country's history. The Civil War boosted the Republican Party's fortunes and catapulted it into majority status at the national level, a status that was further solidified during the Populist realignment in the 1890s. Starting in the 1930s, however, Roosevelt's New Deal reversed the parties' fortunes, bringing the Democratic Party back to national power, and this realignment was further modified by the "culture wars" beginning in the mid-1960s. Each of these...