Senate Republicans today slammed fresh efforts from the White House to dissuade wavering Democrats from backing their plan to fast-track the Keystone XL pipeline, drawing a vocal defense from President Obama's aides and underscoring how close the measure is to reaching a pivotal 60-vote threshold.

The long-running clash over Keystone XL, which would nearly double U.S. import capacity for emissions-heavy Canadian oil sands crude, continues to prove a political headache for Obama despite his administration's avowed support for construction of the 1,700-mile project's $2.3 billion southern leg.

Should today's amendment from Sens. John Hoeven (R-N.D.) and Richard Lugar (R-Ind.) pass, Obama could face the frustrating choice between threatening to veto the transportation bill it is linked to and accepting a public-relations defeat on the pipeline.

The White House's acknowledged work against the Keystone XL plan met with unsurprising alarm from Republicans who hail the Alberta-to-Gulf-Coast link as a job creator that would displace Middle East imports. "It's hard to even comprehend how out of touch he is on this issue," Senate Minority Leader Mitch McConnell (R-Ky.) said of Obama.

Sen. John Cornyn (R-Texas) piled on, declaring that the president "woke up today thinking about how to lobby against jobs," and American Petroleum Institute President Jack Gerard accused Obama of "trying to avoid embarrassment" by calling Democratic senators on the issue.

White House spokesman Clark Stevens fired back via email, accusing the GOP of "trying to play politics with a pipeline project whose route has yet to be proposed." He added that XL sponsor TransCanada Corp. is not ready to announce a final path for the oil link through the flash-point state of Nebraska.

"As the president has made clear, we will ensure any project receives the important assessment it deserves, and the administration will base a decision to provide a permit on the completion of that review, a process that was unfortunately blocked by Republicans in December," Stevens said.

Even as the industry and environmentalist camps zeroed in on a handful of red- and purple-state Senate Democrats whose votes could prove crucial in the final tally -- including Jim Webb of Virginia, Ben Nelson of Nebraska, and Jon Tester of Montana -- their party chief sounded a note of confidence.

"Everyone should just calm down on Keystone," Senate Majority Leader Harry Reid (D-Nev.) told reporters today, indicating that he sees enough votes in hand to block the Keystone XL amendment.

Yet, a narrow loss for the GOP plan makes it even less likely to fade from the congressional stage.

The amendment's sponsors made clear this week that they intend to keep pressing centrist Democrats on the project throughout the year, even as TransCanada pursues a new segmented strategy for the pipeline's construction (E&E Daily, March 7).

Export drama

The Democratic alternative to the Hoeven-Lugar amendment would affirm the administration's existing time frame for evaluating Keystone XL's border-crossing portion while blocking the export of crude or refined products derived from the fuel that would run through the pipeline.

That export restriction is propelling a lobbying battle and controversy of its own, as Republicans and industry groups warn that a Democratic push to curtail fuel shipment overseas risks sapping the goal of a five-year doubling of U.S. exports that Obama himself outlined in 2010.

"If we're going to grow, it's going to be because of exports," the president told an economic summit in November.

White House aides spoke favorably of exports, specifically mentioning the recent boom in U.S. refined product exports, during a meeting yesterday with oil and gas industry representatives, according to a source with knowledge of the event.

The Wyden amendment would "harm refinery workers by limiting their ability to run at full production through an export ban," Lugar's office wrote in a statement this morning. "The U.S. is a huge net importer of oil at approximately 9 million barrels per day."

Reporter Jean Chemnick contributed.