McLeroy is a dentist who was on the Texas School Board. He was a creationist and was one of the key people pushing their agenda (as well as some other extreme right wing positions) on the schools and its textbooks. He was narrowly prevented from serving a second term.
(This clip appeared on April 23, 2012. To get suggestions on how to view clips of The Daily Show and The Colbert Report outside the US, please see this earlier post.)