(MONEY Magazine) – Although former Senator Bob Dole (R-Kans.) probably won't see a dime of interest on the $300,000 he loaned House Speaker Newt Gingrich (R-Ga.) in April for eight years, he will owe taxes each year on the 10% compounding interest. This means that Dole could be hit with as much as $135,000 in taxes on the $343,000 in deferred interest before he cashes a single check from Gingrich.

By contrast, the Speaker may be able to write off the entire $300,000 immediately--if the IRS buys his argument that the payment is a "reimbursement of legal expenses." If Gingrich also successfully argues that the loan was a business expense related to his profession as a politician, he could deduct the $343,000 in interest on his tax returns. Those are two big ifs. But Grant Thornton tax partner Tom Ochsenschlager says: "I'd be surprised if those moves don't save Gingrich more than $150,000 in taxes." --Ann Reilly Dowd