Nobody loves America as Canada does, but you know how the saying goes, to get a friend, be a friend. And in this week’s column for the Globe’s Economy Lab feature (in the ROB), I lay out the case why America is making it hard for its friends to support it in its push to negotiate a Trans-Pacific Partnership. Unless Congress agrees to limit its power unilaterally to rewrite any negotiated agreement, the 11 other parties at the TPP table won’t make their best offers. US bullying is not the solution. Trade Promotion Authority (whereby Congress agrees to vote any final deal up or down without amendment) is.