It's not easy.
I-732 would have been a groundbreaking climate policy, but it was opposed not just by big business but by many environmentalists too.
A battle over a ballot initiative in Washington state has boiled over onto the national scene.
Sanders and four other senators sent a letter to Obama asking him to require a full environmental and cultural review of the pipeline.
After Friday's terrorist attacks, activists and organizers are deciding whether to scale back or cancel some planned events.
Is Keystone permanently dead? Will this decision affect the climate? These answers, and more.
The company asked for a delay in review of the pipeline proposal, hoping to push the decision off to the next president. Obama denied the request.
The pipeline company is asking for a delay in the federal review of its proposal, hoping to get the decision punted to Obama's successor.
Sen. Kelly Ayotte is among a handful of politicians trying to shift the GOP's approach. A recent Conservative Clean Energy Summit had the same goal.