This week, the U.S. State Department gave the Keystone XL pipeline an environmental thumbs up. In its latest report on the project, the department stated that Keystone wouldn't have a significant environmental impact and wouldn't create unacceptable levels of greenhouse gases. So how much longer can Obama stall before making a decision? Can he ignore the 42,000 jobs and $3.4-billion the report suggests Keystone would bring to the U.S. economy? Probably yes. Any decision Obama makes will inevitably alienate part of his constituency, either environmentalists or unionists, so he has an interest in putting it off as long as possible.