President Obama announces support for building an oil pipeline from Oklahoma to Texas, Thursday in Cushing, Okla. Tom Pennington/Getty Images hide caption

itoggle caption Tom Pennington/Getty Images

Demonstrators march with a replica of a pipeline during a protest to demand a stop to the Keystone XL tar sands oil pipeline outside the White House last November. Evan Vucci/AP hide caption

itoggle caption Evan Vucci/AP