Charles Ebinger, the director of Brookings' Energy Security Initiative, doesn't see anything fundamentally disjointed about the administration's embrace of natural gas and the stalled pipeline. Ebinger, who also supports exporting U.S. crude, said there are different regulatory processes governing the two.
Still, he thinks the administration's calculus is as much political as practical. Environmental groups, which last month released an open letter blasting President Barack Obama's energy policy, have hamstrung Keystone's approval.
"Despite all the reports [supportive of the Keystone XL] I don't think he's going to support it and I don't think he's going to do anything" ahead of November's midterm elections, Ebinger said.
(Read more: Keystone pipeline politics 'nuts': Ex-oil chief)
Keystone is not alone in the U.S. queue for regulatory approval. Enbridge, Canada's largest pipeline operator, is also in the midst of an extended waiting period for a plan to expand capacity on its 3,100 mile line—the world's longest—by an additional 120,000 barrels per day.
The Keystone XL "is nothing but politics," said Chip Knappenberger, assistant director for the Center of the Study of Science at the Cato Institute, a conservative group that opposes government regulation generally. He said Enbridge's original pipeline proposal "was a very similar proposal, but it didn't catch anyone's attention."
Unlike natural gas, which is part and parcel of the Obama administration's climate action policy, the Keystone "has a really big environmental line in the sand," Knappenberger said.
"The environmental dangers are minimal compared to trains and trucks and other ways" to ship oil, Knappenberger said. "If the line in the sand wasn't drawn, the pipeline would have flown through."
—By CNBC's Javier E. David. Follow him on Twitter