But Sessions has remained undeterred. Although his office refused to comment for this story, aides familiar with the situation said Sessions has continued to block a unanimous consent agreement to move the GSP — forcing the cloture vote.
With few allies in the House or Senate, Sessions has apparently turned to AMTAC in the waning days of the debate.
Tantillo said that while AMTAC is not opposed to international trade per se, he acknowledged that the group — and the companies it represents — has been opposed to much of the nation's trade policy "of the last 30 years."
Tantillo, who said AMTAC does not "necessarily oppose renewal of GSP," said his organization's primary concern has been with the South Korean trade pact.
"We were not pleased at all with the terms of the Korea agreement" that were negotiated by the Bush administration, Tantillo said, adding that AMTAC "did not believe" the Obama administration should have moved forward with the agreement.
While Tantillo said "there have been times in the past he's supported things we were interested in," a comparison of Sessions' voting record and AMTAC's key votes shows little in common.
Since Sessions was elected in 1997, AMTAC has key-voted five trade bills: fast-track authority for the president in 2002, the Chile and Singapore trade agreements in 2003, permanent most-favored-nation status for China in 2000, the Morocco free-trade deal in 2004 and a Central American free-trade agreement in 2005.
But Sessions only voted against the Moroccan trade deal and the fast-track authority bills. The Senator has voted for numerous other trade agreements that were not designated as key votes by AMTAC, including deals with Oman and Peru, as well as an amendment in 2009 to eliminate "Buy American" provisions of existing law.
A number of Senate aides on both sides of the aisle also noted that Sessions has not raised objections to the South Korean trade deal — nor any of the other agreements tied to the passage of the GSP this week.
Sessions' alliance with the organization has raised eyebrows among Republicans.
"It can't be comfortable to lobby Republican colleagues for an earmark in a trade bill with a protectionist group dedicated to killing free trade. It'll be about as effective as using the Teamsters to persuade the tea party to increase funding for the National Labor Relations Board," a former GOP leadership aide familiar with the situation said Friday.
Rep. Elijah Cummings, D-Md., right, hugs Harold Schaitberger, General President of the International Association of Fire Fighters, after the Congressman spoke at the IAFF's Legislative Conference General Session at the Hyatt Regency on Capitol Hill, March 9, 2015. The day featured addresses by members of Congress and Vice President Joe Biden.