Spot the error-8

From John Cassidy's "Why Won't Mitt Romney Release More Tax Returns?" at newyorker.com: "The principal that if your father also ran for President, and released twelve years of tax returns, then you can release just two and claim the family average is a respectable seven years?"

 

 

 

 

 

 

 

 

Yes, at The New Yorker's website. Principle is the word for a tenet, a rule, a standard. Principal as a noun is either a main participant or the amount of a loan on which interest is calculated.