This post has been updated.

The Senate failed to override President Obama's veto of a bill authorizing construction of the Keystone XL pipeline, severely dimming prospects for its approval in the next two years.

The Senate voted 62 to 37 to override the veto, with eight Democrats joining the chamber's 54 Republicans -- still short of the 67 votes necessary for an override.

The proposed pipeline from oil-rich north central Canada through the American midwest to Gulf of Mexico refineries has emerged as a front-burner issue for both pro-business Republicans and for environmental groups supportive of Democrats, who say the oil transported by the pipeline would accelerate climate change.

The outcome of Wednesday's vote was not a surprise, with votes falling along the same lines as the Jan. 29 vote that sent the bill to Obama, with most of the nine Democrats who initially voted to build the pipeline also voting to override on Wednesday.

A spokesman for TransCanada, the energy company proposing to build the pipeline, said the firm remains "encouraged by the long-standing bi-partisan support for this critical modern infrastructure project."

While Obama has made numerous statements critical of the Keystone XL proposal, and in spite of the veto, the pipeline is still making its way through a permitting process with the State Department, which must approve its crossing of the U.S.-Canada boundary.

"We look forward to the conclusion of the review period and having this project approved on its merits," said Mark Cooper, the TransCanada spokesman. "Keystone XL clearly satisfies all of the stated National Interest Determination criteria, it passes the environmental test of not significantly exacerbating GHG emissions, will enhance U.S. energy security and provides economic benefits to the nation through privately funded job creation and economic stimulus."

Meanwhile, environmental advocates hailed the override's failure.

"Senate Republicans have shown just how out of touch they are with the priorities of American families with their repeated attempts to force approval of the Keystone XL tar sands pipeline," Sierra Club Executive Director Michael Brune said in a statement. "The decision to deny this dangerous project belongs to President Obama alone, and we are confident he has all he needs to reject it once and for all."

Actor and environmental advocate Robert Redford published an MSNBC op-ed Wednesday calling on Obama to "reject the dirty tar sands pipeline once and for all."

The Democrats supporting the veto override were Michael Bennet (Colo.), Tom Carper (Del.), Robert Casey (Pa.), Heidi Heitcamp (N.D.), Joe Manchin (W.V.), Claire McCaskill (Mo.), Jon Tester (Mont.) and Mark Warner (Va.).

Joe Donnelly (Ind.), who was the ninth Democrat voting in January to build the pipeline, did not vote Wednesday. An aide said he was in South Bend, Ind., on Wednesday for the funeral mass of the Rev. Theodore Hesburgh, the former University of Notre Dame president.

A two-thirds vote of both houses of Congress is necessary to override a presidential veto.

This post was corrected at 11:52 a.m. on March 5. Redford's op-ed was published by MSNBC, not Bloomberg.