ST. PAUL, Minn. (AP) — Years before Burger King sized up a Canadian headquarters in a hunt for lower taxes, Republican U.S. Senate candidate Mike McFadden's investment firm was involved in a merger that moved an American pharmaceutical company to Ireland and significantly dropped its tax rate. McFadden's Minnesota-based firm made more than $11 million, according to public filings. The 2012 deal came at the foot of a recent wave of so-called tax inversions in which U.S.