The Senate on Tuesday handed President Barack Obama the biggest legislative victory of his second term, with a dramatic vote clearing the way for major trade agreements with Pacific Rim nations and the European Union.

The vote all but ensures the passage of legislation that will allow Obama to "fast-track" the trade pacts he negotiates through Congress, preventing filibusters or amendments. Liberals have long assailed Obama's trade agenda, but Republicans successfully wooed a bloc of Democrats led by Sen. Patty Murray (D-Wash.) and Ron Wyden (D-Ore.) to secure enough votes to overcome a filibuster.

The vote came down to the wire, thanks to an eleventh-hour reversal by Sen. Ted Cruz (R-Texas), who announced his opposition in a bombastic an op-ed for Breitbart News that sent Majority Leader Mitch McConnell (R-Ky.) scrambling for additional Democratic support.

With the 60-vote threshold clearred, the path is now open for the Senate to take a final vote on the legislation on Wednesday.