Because he's very serious and can get things done:
He's been in Congress for nearly 13 years, but Rep. Paul Ryan (R-Wis.) has only seen two of his bills pass into law during that time.
Ryan, who Mitt Romney has tapped as his running mate, passed a bill into law in July 2000 that renames a post office in his district. Thanks to Ryan, the post office on 1818 Milton Ave. in Janesville, Wis., is now known as "Les Aspin Post Office Building."
The other time Ryan saw one of his bills become law was in December 2008, with legislation to change the way arrows (as in bows and arrows) are hit with an excise tax. Specifically, his bill amended the Internal Revenue Code to impose a 39-cent tax per arrow shaft, instead of a 12.4 percent tax on the sales price. The bill also "includes points suitable for use with arrows in the 11 percent excise tax on arrow parts and accessories."