Later this afternoon, the Senate will hold a procedural vote on Trade Promotion Authority (TPA) in an attempt to reach cloture and guarantee a floor vote on fast-track authority for Barack Obama on the Trans-Pacific Partnership (TPP) free-trade agreement. On its first go-around, TPA barely made it past this procedural hurdle, with only 13 Democrats coming along for the ride — and that package included Trade Adjustment Assistance (TAA), a key Democratic priority to buffer the effects of globalization for American workers. Without it, even those few Democrats may take a pass on TPA, which would once again put fast-track...