Hillary Rodham Clinton won a decisive two-to-one victory in Kentucky, a state located in the Appalachian region which had many of the demographics in her favor. According to exit polls, 89 percent of voters in the Kentucky Democratic Primary were Caucasian and they opted for Clinton by a margin of 72-23 compared to the 9 percent of African American voters who backed Obama by a margin of 90-7. Clinton won all age groups, all socioeconomic/income classes and educational attainment ladders of voters. Registered Democrats, who comprised 84 percent of the turnout, backed Clinton by a margin of 68-30. She also won all ideological groups. Regarding religion, Clinton dominated all major denominations by two-to-one margins, including Protestants which backed her 66-28, Roman Catholics supported her 66-31, and other Christians favored Clinton by a margin of 66-30. It was a conclusive landslide victory for Clinton.
Clinton performed extraordinarily well throughout the state of Kentucky, carrying every county with well over 60 percent of the vote and winning all but two: Jefferson County, which contains Louisville, and Fayette County which contains Lexington-Fayette. Her best performance was in Southeast Kentucky, located in the heart of Appalachia, an area made up of less educated, lower-income, working-class whites. In fact, it was here where Clinton received her largest margin of victory in a county nationwide: Magoffin County gave Clinton 92.98 percent of the vote while Obama only received a meager 5.00 percent.
Kentucky was another state that highlighted Barack Obama's growing problem among working-class whites, a swing voting bloc also referred to as Reagan Democrats who Clinton claimed were crucial to Democrats winning back the White House. Exit polls in Kentucky supported Clinton's claim – of Kentucky voters who voted for Clinton, only one-third of voters said they would vote for Obama should he become the nominee while another one-third said they would vote for presumptive Republican presidential nominee John McCain and another one-third said they would not vote at all.