Former Vice President Joe Biden vowed Monday to stop the Keystone XL pipeline “for good” if elected president.MThe pipeline, to carry oil from Canada’s tar sands into the United States, was blocked by President Barack Obama for years, even though it had passed an environmental review. The Obama administration stopped the project under pressure from radical environmentalists over concerns about climate change — though the alternative to the Keystone XL was simply that the oil would be exported from Canada to China, rather than to the U.S., and used there instead. The Obama administration’s hostility to the pipeline complicated relations with Canada and led to a 2016 lawsuit by TransCanada, the company involved in the project, claiming Obama breached the terms of the NAFTA trade deal. There was substantial public support for the Keystone XL project among local residents along the pipeline route. Organized labor also supported the project, anticipating the creation of thousands of direct and indirect jobs. At one point the Teamsters union withheld support for Hillary Clinton in 2015 over her flip-flop against the Keystone XL.