Senator Ron Johnson, Republican of Wisconsin, on Thursday. : Two Republican senators who had previously opposed the bill for its treatment of so-called pass-through businesses, Ron Johnson of Wisconsin and Steve Daines of Montana, now say they will vote for the legislation. The Senate tax bill allows pass-through owners to deduct 17.4 percent of their business income as a way of lowering their taxes. Republicans were planning to increase the deduction to 20 percent to address the concerns over how pass-through owners were being treated by the bill.