When opponents sought to modify the tariff bill to allow for an income tax, Taft opposed it on the ground that the Supreme Court would likely strike it down as unconstitutional, as it had before. Instead, they proposed a constitutional amendment, which passed both houses in early July, was sent to the states, and by 1913 was ratified as the Sixteenth Amendment. In the conference committee, Taft won some victories, such as limiting the tax on lumber. The conference report passed both houses, and Taft signed it on August 6, 1909. The Payne-Aldrich tariff was immediately controversial. According to Coletta, "Taft had lost the initiative, and the wounds inflicted in the acrid tariff debate never healed".