There's an obvious reason why Keystone opponents aren't wedded to public sentiment right now: The vast majority of Americans support the project.
A Pew Research Center poll released Tuesday found 66 percent of Americans back the project, as opposed to 23 percent who oppose it.
A Washington Post poll in June found similar results, with 59 percent in favor and 18 percent against. Just 34 percent said the pipeline would do significant harm to the environment, while 83 percent believed it would create a significant amount of jobs.
"The politics of this are not perfectly on our side," is the way Burton put it to reporters, adding later that in his experience, "The president has not been driven by things like legacy and polls, and more driven by policy, the best possible policy."
LCV and other environmental groups are working to change the public's perception of Keystone. The group's senior vice president for government affairs, Tiernan Sittenfeld, told reporters climate activists will launch a campaign to convince Americans the project is "all risk and no reward."
And if Obama signs off on Keystone, does Burton think it will undermine the mantle of climate warrior that he laid out in his second inaugural address and 2013 State of the Union speech?
"I do think that all of these things will be considered in the aggregate when people look back at the Obama presidency," Burton said.