As bicameral transportation talks begin to home in on the politically volatile Keystone XL pipeline, Republicans' prospects for tying the Canada-to-U.S. oil line to a final deal appear to rest on their ability to woo at least two more Democratic senators.

Sen. John Hoeven's (R-N.D.) plan to push the pipeline past a presidential rejection coaxed 11 Democrats to the side of a united GOP in March, drawing 58 votes in a chamber where 60 are needed to pass almost any contentious measure. Peeling off two more senators in the president's party would lend a sense of inevitability to the Republicans' quest for a fast-tracked Keystone XL -- but their recent confidence on the pipeline push got a reality check yesterday courtesy of Transportation Secretary Ray LaHood.

Pipeline sponsor TransCanada Corp. has filed a new application to build its $5.3 billion bid for a near-doubling in U.S. import capacity of Canadian oil sands crude, but "no single, final pipeline route has been identified and assessed for its potential impacts, including impacts on health and safety, the economy, foreign policy, energy security, and the environment," LaHood wrote to Environment and Public Works Chairwoman Barbara Boxer (D-Calif.) in a letter obtained by E&E Daily.

While the Obama administration reiterated its threat to veto any transportation bill that expedites the Keystone XL review process, lawmakers were tight-lipped on who, if anyone, in the Senate Democratic caucus is being courted on the issue.

Rep. Ed Whitfield (R-Ky.), a House Energy and Commerce subcommittee chief who sits on the 47-member transportation conference panel, said yesterday that while he is not yet involved in reaching out to Democrats, there is "contact going on between various people over here" and in the upper chamber.

Some members already are meeting in smaller groups, including Environment Committee ranking Republican James Inhofe of Oklahoma and House Transportation and Infrastructure Chairman John Mica (R-Fla.), who is also set to meet today with Boxer. House Republicans have "pre-met," sometimes with staff involved, and plan a bigger catch-up session today, Mica added, while an Environment and Public Works aide said Boxer also would meet with other conferees.

Mica said he had heard positive signs from staff and other members on Keystone but had not been fully briefed on progress on that front.

The 58-vote showing for Hoeven's bill turned the spotlight on a handful of Democrats who voted "no" two months ago but could decamp as Republicans turn up the pipeline pressure (E&E Daily, March 9). Chief among them are Sen. Ben Nelson (D-Neb.), a supporter of the project who has said frequently that he wants to let the Keystone XL rerouting process play out in his home state, and Sen. Tim Johnson (D-S.D.), a member of the transportation conference through whose home state the pipeline would run.

Johnson has said in the past that he opposes the inclusion of the Keystone language on the transportation bill.

Environmentalists in the Cornhusker State, who continue to battle the pipeline's sponsor over what they call a continuing threat posed by Keystone XL to the state's Ogallala Aquifer, do not see the soon-to-retire Nelson as wavering on the Hoeven bill.

"I never speak in terms of absolutes in the political realm, but Senator Nelson has been firm on this all along," Ken Winston of the Nebraska Sierra Club said in an interview. "I don't see any reason why he would change his position."

That the Democrat vying to take Nelson's seat next year, former Sen. and Gov. Bob Kerrey, is similarly in favor of letting the environmental review in Nebraska take its course could provide even more reason for the incumbent to stay a firm "no," Winston added.

Election-year winds could pull two other Democrats who voted "no" on Hoeven's bill in March either toward or away from Keystone XL as the transportation conference talks continue.

Sen. Mark Warner split from his fellow Virginia Democrat Jim Webb, who supported the pipeline. Like Nelson of Nebraska, however, Warner faces a Democratic nominee -- his successor as Virginia governor, Tim Kaine -- whose position against pushing through the project may affect his decisionmaking.

Bill Nelson is also facing a tough election challenge from Rep. Connie Mack (R-Fla.), who has repeatedly hit Nelson in the past for aligning with Obama on the pipeline decision. In a recent TV ad, the pro-Mack Freedom PAC super-PAC accuses Nelson of choosing to "side with President Obama over the people of Florida."

The inclusion of language that sends fine money from the BP PLC oil spill to Gulf Coast states could also serve to sway Bill Nelson. He fought for the inclusion of the so-called "RESTORE Act" -- which would send 80 percent of the Deepwater Horizon spill penalty money to five Gulf Coast states -- in the Senate bill and is serving on the conference in part to protect that section. Although RESTORE reflects an area of compromise for the House and Senate, Senate conferees are fighting for the inclusion of their more comprehensive language.

How many firm 'yes' votes?

Further complicating the Keystone XL calculus is the potential for Democratic senators who backed Hoeven's pipeline bill in March to back a "clean" transportation bill rather than open the door for further controversial additions to a typically bipartisan measure.

Sen. Ron Wyden of Oregon said yesterday that in the past few days, he has begun to sense that fellow Democrats who backed Keystone XL in March may not be willing to yoke the pipeline to the transportation package.

"Senators are seeing that this is probably the big jobs bill between now and the end of the session," Wyden said. "There are far more jobs in the transportation bill than there are in the Keystone effort."

One of those Hoeven-aligned Democrats, Bob Casey of Pennsylvania, said only that "we'll see" when asked yesterday how he would reconcile his March "yes" vote with the GOP bid to attach the pipeline to the transportation proposal. The Senate's "two-year bill," he added, "is 70,000 jobs in Pennsylvania."

Industry-backed studies predict that Keystone XL would create 20,000 direct jobs. Green groups dispute that number, and the Obama administration has projected that 13,000 jobs over the project's two-year construction phase would result from a green light.

House Republicans challenged the Democratic depiction of the choice at hand as either a swift new transportation bill or the jobs that the pipeline would generate. "We can add 20,000 more jobs on top of what they're adding" by attaching the XL line, Whitfield said.

Administration weighs in

LaHood's letter -- also sent to Inhofe, Mica and Rep. Nick Rahall (D-W.Va.) -- also states the administration's opposition to the environmental streamlining language in the House bill, which many environmentalists have criticized as going too far. LaHood says the language would "add substantial administrative burden and complexity and would risk undermining the National Environmental Policy Act."

Language in the House bill that would bar U.S. EPA from regulating coal ash also got a mention, with LaHood saying that the administration opposes its inclusion.

A final bill, LaHood said, should include reforms that would speed up project delivery without harming NEPA and should promote multimodal transportation programs. The secretary specifically mentioned the inclusion of the TIGER livability grant program, which he said would promote alternative transportation and offer a "catalyst" for rail and freight infrastructure projects.

Click here to read the letter.

Reporter Manuel Quinones contributed.