Other mistake: The actress who plays Nancy McNally, Anna Deavere Smith, sometimes has her name spelt Anna Deveare Smith in the credits. It's happened in quite a few episodes. Not sure which is the correct way.
Factual error: Whenever the king of Sweden is mentioned by name they always refer to him as "King Gustaf." The king of Sweden is actually named Carl XVI Gustaf. His given name is Carl Gustaf and he holds the throne as the sixteenth king Carl. Thus they should refer to him as "King Carl Gustaf" or, less common but technically correct, "King Carl." Since Bartlet has met the Swedish king in person and talked to him about Ellie's mathematical skills he ought to know the correct name.
Answer: It's in reference to the many televangelists and revival ministers usually associated with the right-wing that have been convicted of tax fraud (Jim Bakker and Tamy Faye being a more famous set). Occasionally, the more unscrupulous ministers have bilked millions from believers all in the name of God.
Nikki