A key component of President Barack Obama's trade agenda and his economic legacy failed a critical test in the Senate today as Democrats blocked consideration of a bill that would give the president "fast track" authority to negotiate a massive 12-nation trade pact.
The vote was 52-45 and effectively kills consideration of "fast track" authority until Democrats withdraw their request that the Senate also vote on a customs bill which includes currency manipulation and enforcement provisions that Democrats support.
The bill, known as Trade Promotion Authority, would have given the president so-called "fast track" authority to negotiate the Trans-Pacific Partnership trade pact without the threat of congressional filibusters or added amendments. The measure faced its first test today when the Senate considers a procedural motion to start consideration of the bill.
The vote marks a major set-back for President Obama's call for fast-track authority to negotiate the 12-nation Trans-Pacific Partnership. While President Obama knew he would need to rely heavily on the support of Republicans, he was also relying on pro-trade Democrats to move "fast track" forward.
That motion needed a considerable chunk of Democrats to obtain the 60 votes needed to advance. But many Democrats are reluctant to lend their support unless they are given assurances that Congress also considers their priorities related to trade.
Those Democrats include Sen. Elizabeth Warren of Massachusetts, a former Obama administration official turned legislator, who has been one of the most vocal critics of the president's handling of the trade accord — handling she says has lacked transparency.
"The president said in his Nike speech that he's confident that when people read the agreement for themselves, that they'll see it's a great deal," Warren told the Washington Post. "But the president won't actually let people read the agreement for themselves. It's classified."
The president has said Warren's perspective, and those of Democrats with similar reservations, is "wrong."
Still, the White House is keenly aware that it has had trouble shoring up Democratic support.
The president, senior White House staff and cabinet secretaries have been pitching members of Congress privately for weeks. There's also a clear public relations strategy with the president talking the deal up in interviews with David Letterman, MSNBC's Chris Matthew and NPR's Steve Inskeep and his trip last week to Nike's headquarters in the liberal-leaning community of Portland to make the case for the trade deal.
"...The President has been trying to do his part to make the case to Democrats, some of whom started out reluctant," White House press secretary Josh Earnest told reporters on Monday. He added that the president feels there's "reflexive opposition that exists in many corners of the Democratic Party about trade agreements. And the case that the President made in private is very similar to the case that the president has made in public...he's made a very strong case about why he believes this is in the best interest of our economy both in the short term and over the long term."
The trade pact, which would be the largest since President Bill Clinton completed NAFTA in 1994, is largely considered one of President Obama's top priorities during his last two years in office.
But the Trans-Pacific Partnership, and the fast-track bill which must precede it, has deeply divided Democrats, and put Republicans in the strange position of siding with the president. While the vast majority of Republicans support the trade pact, many Democrats oppose it saying it will cost American jobs and result in lowered middle class wages.
Leadership aides on both sides of the aisle doubted there would be the 60 votes needed to move forward with consideration of the 'fast track" authority measure, with many saying it would largely depend on what Senate Majority Leader Mitch McConnell, a Kentucky Republican, decided to include in the package.
Democrats threatened to stall consideration of the "fast track" authority measure unless McConnell assured passage of three additional bills, including a customs bill that includes currency manipulation provisions favored by Sen. Chuck Schumer, a New York Democrat, and other members of his party, but that Republicans fear will tank the negotiating process for the Obama administration.
"I think it's going to be very difficult to pass because there's real uncertainty about what McConnell's plans are," Senate Minority Whip Dick Durbin, an Illinois Democrat, earlier told reporters of Tuesday's procedural vote. "It comes down to the customs issue, which includes the currency issue and includes enforcement issues and a lot of other things."
A small number of Republicans also opposed the measure.
Sen. Jeff Sessions, an Alabama Republican, has been a vocal opponent of the trade pact. Seven Democrats supported moving the legislation out of the Senate Finance Committee to the floor for consideration, while five Democrats voted against it.
While President Obama has been actively lobbying Democrats to support "fast track" authority, according to a Senate Democratic aide President Obama cancelled a planned meeting with persuadable and pro-trade Senate Democrats on Monday.
Today's vote, and consideration of trade legislation, was further complicated by the two must-pass pieces of legislation facing Congress: a reauthorization of the bulk-data collection program which is part of the Foreign Intelligence Surveillance Act, or FISA, as well as transportation funding, both of which expire at the end of the month.
Senate Minority Leader Harry Reid, a Nevada Democrat and a staunch opponent of "fast track" authority on the trade measure, has told McConnell he believes they should focus on FISA and transportation funding first, as consideration of both pieces of legislation will likely take a considerable chunk of time.
The move was also widely seen as a tactic to delay consideration of "fast tracking" on the trade accord.
"I'm confident we will have the votes to move forward," Senate Majority Whip John Cornyn, a Texas Republican, told reporters late last week, "It's going to be a test for the president, whether he can produce enough Democrats."
NBC News' Kristin Donnelly contributed reporting. This article originally appeared on NBCNews.com.