Joanna Sopinska contributed to this article
On 16 April, a Trade Promotion Authority (TPA) bill , which will let the US president submit a future trade deal for congressional approval for a simple up or down vote, was introduced. It was co-sponsored by three of the four committee leaders on trade on Capitol Hill: Senators Ron Wyden (Democrat, Oregon), Orrin Hatch (Republican, Utah) and Congressman Paul Ryan (Republican, Wisconsin). But the top House Democrat on trade, Sandy Levin (Democrat, Michigan)…