Thousands protest Canada-US pipeline

ROUGH CUT - NO REPORTER NARRATION
Thousands of protesters opposed to a new oil pipeline from Canada to the United States circled the White House grounds on Sunday to press President Barack Obama to reject the project for environmental reasons.
Opponents to TransCanada Corp's Keystone XL pipeline, which would transport crude produced from oil sands, have dogged the president for months, arguing that the carbon emissions produced in the process of extracting oil from the sands would exacerbate climate change.
Men and women, many of them wearing orange vests with "Stop the pipeline" printed on them, lined up around the White House grounds, which include the presidential mansion, the U.S. Treasury department and a sprawling executive office building.
The pipeline controversy threatens to loom over the 2012 presidential race. Obama faces political pitfalls whether his administration approves or rejects the project.
A decision in favor would support Obama's goal of creating jobs and diversifying U.S. energy sources, but it would alienate core Democratic supporters who are already disappointed by his progress in fighting climate change.
Obama was not at the White House when the protest took place. As he often does on the weekends, the president was playing golf.