Today’s big Senate trade vote, explained

The Senate will vote today on legislation that could finally give President Barack Obama Trade Promotion Authority (TPA). The measure would guarantee trade deals he negotiates an up-or-down vote from Congress, smoothing the way for the controversial Trans-Pacific Partnership deal with about a dozen Pacific Rim nations.

Obama and Republican leaders in Congress have struggled to pass TPA legislation over the past few weeks. Back in May, the Senate passed a trade package that combined TPA with an extension of Trade Adjustment Assistance (TAA), programs to help workers whose jobs are displaced by foreign competition. But this package died in the House — Republicans were unwilling to vote for TAA, which they viewed as wasteful government spending, while many House Democrats wanted to stop a trade agreement they saw as a bad deal.

So last week, the House passed a standalone TPA bill and sent it back to the Senate. The difficulty was that Republicans in the Senate needed help from a few Democrats to overcome an expected filibuster. And these Democrats have refused to vote for TPA unless the assistance for displaced workers was included. For a while, it seemed like the gridlock would doom Obama’s whole trade agenda.

Now congressional leaders appear to be on the verge of a compromise. Republican leaders have promised that once TPA has passed, they will bring up TAA for a separate vote. And with TAA no longer tied to TPA, it should receive broad support from Democrats, easing its passage. At least that has been Senate Majority Leader Mitch McConnell’s (R-KY) pitch to wavering Senate Democrats.

But the vote will be close. The package needs 60 votes to overcome a filibuster, and the Senate’s previous trade bill passed by a 62-38 vote, leaving just two votes to spare. That means Obama and McConnell will need the support of almost all of the 13 Democrats who supported the first trade bill to pass the new bill. And despite intense lobbying from the president, several of these Democratic senators have refused to commit to supporting the legislation over concerns that aid for workers might not actually pass.