The IRS is turning up the heat on Al Sharpton by issuing a string of subpoenas to donors for his National Action Network. Following up on the probe begun by Andrew Cuomo last fall, the IRS and U.S. Attorney's Office have asked Anheuser-Bush to release charitable records and plan to ask inquire with several more major givers. Anheuser-Busch gave between $100,000 and $499,000 to NAN last year alone. According to the Post, Sharpton's group owes millions in back taxes on such gifts. "I think that this is a clear, transparent political investigation," Sharpton said, "because if they started an investigation in December, why would they be subpoenaing people after December unless they are on a fishing expedition?" Sharpton did not say why or what the political agenda of the investigation would be, but we imagine he'll find plenty of ways to explain it to us in the coming weeks.