Oklahoma is part of a geographical region characterized by conservative and Evangelical Christianity known as the "Bible Belt". Spanning the southern and eastern parts of the United States, the area is known for politically and socially conservative views, even though Oklahoma has more voters registered with the Democratic Party than with any other party. Tulsa, the state's second largest city, home to Oral Roberts University, is sometimes called the "buckle of the Bible Belt". According to the Pew Research Center, the majority of Oklahoma's religious adherents – 85 percent – are Christian, accounting for about 80 percent of the population. The percentage of Oklahomans affiliated with Catholicism is half of the national average, while the percentage affiliated with Evangelical Protestantism is more than twice the national average – tied with Arkansas for the largest percentage of any state.