In what is being termed a humiliating defeat for President Obama, House Democrats turned against the White House on a key vote on his trade agenda. reports:

In a dramatic defeat for the White House, President Obama's trade agenda ran aground in the House on Friday as Democrats banded together in opposition despite a personal plea from the president.

In a 302-126 vote, the House killed the so-called Trade Adjustment Assistance bill -- a program that retrains workers displaced by trade. The bill was originally put on the table as a sweetener to help entice recalcitrant Democrats to back the president's main agenda item, a bill that would give Obama "fast-track" authority to negotiate trade deals. 

But the president's own party is so opposed to that legislation, they voted down the sweetener. In a major defection for Obama, even House Democratic Leader Nancy Pelosi joined the rebellion in opposing TAA minutes before the vote. Though she supports the worker aid, she said voting against it was the only way to "slow down the fast track."

She said the main trade bill would be "stuck in the station" without TAA.

White House Press Secretary Josh Earnest tried to put a positive spin on the situation, saying the dramatic turn of events was a "procedural snafu."

"To the surprise of very few, another procedural snafu has emerged. These kinds of entanglements are endemic to the House of Representatives," he said.

Earnest recalled that he used the same phrase a month ago when Senate Democrats opposed the White House on the trade agenda.

He said the president remains committed to passing the legislation with bipartisan support and to "expanding economic opportunity for middle-class families."

Another House vote could come next week. 

"Special Report" host Bret Baier reacted this afternoon, telling Martha MacCallum that the president was given a "huge rebuke" today by Democrats and labor unions. 

Baier said this is "one of those days" when it's really difficult to be the White House spokesman. 

"For [Earnest] to say that the president went up to talk to Democrats today to get their vote and it was a productive meeting, and then the vote that comes out of that meeting is 302 to 126 - a massive defeat when you have to pass two bills to get this trade agenda to go through - is laughable on a lot of levels," said Baier, explaining that Democrats are no longer "stepping in line" with the president.

Watch Earnest's remarks above and Bret's reaction below.

Tune in to "Special Report," tonight at 6p ET for the latest developments and powerful analysis of today's big vote on Capitol Hill.