This is interesting:
From relapsed catholic : "'During the 1990s, J. Budziszewski rose to prominence as one of the leading intellectual lights among Evangelical Christians in America. A political theorist with a special interest in the natural-law tradition, he was highly sought as a speaker at conferences organized by groups such as the InterVarsity Fellowship and Campus Crusade for Christ. (...) 'For some Evangelical Protestants, then, it came as a jolt when, on Easter Sunday 2004, Budziszewski was received into the Catholic Church. After maintaining a public silence about his conversion for several months, Budziszewski agreed to tell the story to CWR...'"
I'll bet it was Aquinas that moved him across the goal line.