Apologies for the late reply, this is the first chance I've gotten around to it.

During contract negotiations 97% of UPS Teamsters authorized a strike. This was widely lauded as an impressive show of militancy. Later only 86% of the 58% of eligible UPS Teamsters voted for the contract, or a little under half of the Teamsters at UPS. Rushing a contract vote and not engaging members in it is a regular tactic of union leadership that wants to reach a compromise and their ability to mobilize a strike vote shows that union officials were more than capable of reaching more members.

Shortly before the contract vote, A small group of Teamsters were organizing against it. They released this article in Cosmonaut and did an interview on Revolutionary Left Radio detailing extensively how many of the supposed victories in the contract were far from that. Employee tiers remained, the air conditioning concessions that were widely celebrated were overstated, and concessions had been made.

Shortly after the contract ratification Labor Notes, who loudly supported the TA before the vote, released this article detailing the many Teamsters that would have preferred a strike.

As detailed in the Cosmonaut article, communists, socialists and progressive labor widely supported the TA even after the actual rank and file Teamsters had overwhelmingly voted in favor of striking. Now we are seeing the opportunist reactionary labor aristocrat Shaun O'Brien that they all fell in line behind show his true colors.