Since the mid-20th century, Miller County has transitioned from reliably Democratic to steady Republican in national, state and local elections. Miller County was part of the Solid South, a period of Democratic hegemony which began after Reconstruction following the Civil War. This resulted essentially in a one-party system, in which a candidate's victory in Democratic primary elections was tantamount to election to the office itself. The Solid South started to dissolve following the Civil Rights Act in 1964, which is when Miller County's streak of supporting Democratic candidates ended. The county would support every Republican presidential candidate after 1964, with exceptions for fellow Southerners: Alabama Governor George Wallace in 1968, Georgia Governor Jimmy Carter in 1976, and fellow Arkansan Bill Clinton in 1992 and 1996. Republican strength has been growing rapidly in Miller County, supporting George Bush with 53 and 58 percent of the vote, supporting Barack Obama’s opponents with 66 and 69 percent of the vote, and supporting Donald Trump with 70.2 percent of the vote.