“Once the decision is out, there is room for Congress to act,” she added. “There’s an opportunity.”
Environmentalists, meanwhile, cheered. League of Conservation Voters President Gene Karpinski called the decision “huge!” in a statement. “The president is showing the world that our country is committed to a clean energy future that will limit carbon pollution and protect the health of our kids and future generations,” he said.
Bill McKibben, the founder of grassroots environmental group 350.org, called Friday "a day of celebration," saying that the decision marked "the first time in history a world leader has turned down a major infrastructure project because of its impact on the climate."
The pipeline has been under review by the administration for years as officials have sought to determine whether approving a cross-border permit to build Keystone XL would be in the national interest.
During that time, players on both sides have criticized the president for failing to make a decision.
The pipeline has also loomed large over the 2016 race, especially on the Democratic side. Sen. Bernie Sanders touted his long-time opposition to the project from the start of the race as proof that his environmental record was stronger than Hillary Clinton’s, who had declined to take a stand on the project. In September, however, Clinton reversed course and announced her opposition, a decision met with cheers from environmentalists and progressives.
On the Republican side, all candidates have said they support the project, with some even promising they’d act to approve it on day one in the White House. Multiple GOP White House hopefuls attacked the rejection; Jeb Bush called it a “self-inflicted attack on the U.S. economy and jobs.”
The pipeline decision stands out as one of the last major environment and climate announcements to arrive during a second term where Obama has made climate change a major focus. The White House has rolled out an aggressive environmental agenda during the president’s second term, releasing a litany of regulations designed to curb greenhouse-gas emissions from everything from trucks to power plants.
In recent months, speculation has intensified that the president would reject the project. Obama had previously pledged that he would not greenlight the pipeline if it worsened global warming. The State Department concluded that Keystone XL would have minimal environmental impact. But Obama called oil-sands extraction “extraordinarily dirty” in March of last year and has downplayed the potential for the pipeline to create jobs and give the economy a lift.
“It’s not going to be a huge benefit to U.S. consumers. It’s not even going to be a nominal benefit for U.S. consumers,” Obama told reporters at the White House in December 2014.
Still, Obama has also faced intense pressure from some labor unions, a key Democratic constituency, to approve the pipeline as a result of the pipeline’s job-creating potential. Those competing pressures have pulled the president in different directions and transformed Keystone into a politically contentious issue for the White House, and one which, for years, it seemed that the president would rather avoid.