On Monday, during a speech at the White House to the National Governors Association, President Trump renewed his commitment to simplifying the tax code, adding As Republicans in Congress work with the President on making these goals a reality, the highly contentious border-adjustment tax has quickly become a hot button issue both inside the party, and among the opposition. The tax, which is an income tax levied on imported goods sold domestically, is championed by House Speaker Paul Ryan, Dow Chemical CEO Andrew Liveris and the President himself.