Republican hopes of wedding the Keystone XL pipeline to a long-term transportation bill rose yesterday after Sen. Max Baucus (D-Mont.), a backer of the politically incendiary $7 billion project, said he expects to join a conference on the bill with House Republicans who have long sought to override President Obama's rejection of the Canada-to-U.S. oil link.

Senate Majority Leader Harry Reid (D-Nev.) still has not made an official announcement on who would join talks to merge the Senate's two-year transportation bill with a House-passed 90-day extension, which includes language fast-tracking the Keystone XL project. Several expected conferees could not confirm yesterday whether they would serve, but an announcement is expected to come today.

Sen. Jay Rockefeller (D-W.Va.), who oversaw rail and safety language as chairman of the Commerce Committee, said he thought the delay in the announcement was due to "a question" over Baucus. When asked, Rockefeller said it had something to do with Keystone XL.

Republicans have pressed four floor votes in less than a year aimed at forcing Obama's hand on Keystone XL, which would nearly double U.S. import capacity for emissions-heavy Canadian oil sands crude, and saw its permit bid denied by the White House in January, a move that thrilled environmentalist supporters of the president.

Signs that the fourth time could be a charm for the GOP began accumulating Thursday, when the House mustered 293 votes for a GOP bid to begin conference talks with the Senate that also would press the pipeline forward despite Obama's permit denial. But White House resistance last month kept the XL link either two or three votes shy of the magic number 60 in the Senate, leaving the GOP to hope for behind-the-scenes backing.

Baucus, chairman of the influential Finance Committee, broke from his party leader three months ago by telling E&E Daily that he considered fast-tracking Keystone XL on the table during high-profile payroll tax cut negotiations -- mere hours after Reid had signaled that the pipeline should not be part of any final deal (E&E Daily, Jan. 25). Should Reid name Baucus to the conference, the Finance chairman would be well-positioned to again side with Republicans on the pipeline, a twist that could embarrass congressional Democrats and a president who already has threatened to veto a transportation bill yoked to Keystone XL.

A Baucus spokeswoman affirmed yesterday that while "no one is a bigger supporter of the Keystone pipeline than" the Montanan, through whose state the pipeline would run, he would not push for a plan to fast-track the pipeline that could not win Obama's support.

"He is looking for every opportunity to help move the project forward," the spokeswoman said, adding that Baucus "will not put more than 1 million American jobs supported by the highway bill in jeopardy unless he's sure whatever the Keystone measure proposed has the legs to pass Congress, be signed into law and stand up to legal scrutiny, so we don't end up delaying the project even further by getting it tied up in the courts."

Long-standing ties between Reid and Baucus diminish the prospects for any large-scale defection on the latter senator's part. Whether some of Baucus' colleagues in more precarious electoral situations -- the Finance chief is not up for re-election until 2014 -- join his cause, however, remains an open question that could force Reid and the White House into a compromise on the pipeline.

"I have heard that various Democratic senators, who support KXL but have given their votes to leadership up until now, are starting to tell leadership that their patience is running thin and that they want to put this issue behind them," a refining industry source said yesterday via email, candidly addressing the issue on condition of anonymity. "They are beginning to think that the transportation conference may give them that opportunity."

Sen. Barbara Boxer (D-Calif.), who has been leading the transportation effort in the Senate, told reporters yesterday she had no indication that Keystone XL would be an issue when choosing conferees. "Keystone may not come up, it may come up, we don't know," she said about the conference.

Boxer said the conferees and ratios would come "very soon" and that there had not been enough time since the House passed its extension to even call it a delay.

Meanwhile, the shape of the committee became slightly clearer. Rockefeller said he would be on it, while key Republicans indicated last night that they expected to be named. Sen. James Inhofe (R-Okla.), who co-sponsored the bill with Boxer, said "I'd better be" on the committee, while Sen. Richard Shelby (R-Ala.) said he hoped to be.

Shelby, as ranking member of the Senate Banking, Housing and Urban Affairs Committee, oversaw the transit section of the bill with Chairman Tim Johnson (D-S.D.).

The House is scheduled to vote tomorrow on a motion to go to conference with the Senate. Presumably, House conferees will be announced then.

Lawmakers are mixed on whether a House amendment to pre-empt U.S. EPA's forthcoming regulations on the disposal of coal ash will survive in conference.

The amendment would insert West Virginia Rep. David McKinley's H.R. 2273 into the transportation bill, preventing EPA from designating the combustion waste as hazardous but creating minimum national guidelines for state enforcement.

"I think it will" make it through, Inhofe said, "because there is enough anxiety to get this thing passed."

But Rockefeller, a co-sponsor of the Senate version of the bill, was more pessimistic. "I think it will disappear," he said.

Supporters of stronger coal ash rules at the federal level are highlighting the amendment's connection with the controversial American Legislative Exchange Council, the conservative group under fire for its role in developing stand-your-ground self-defense laws. ALEC also supports state oversight of coal ash.

When asked to speculate about conference committee outcomes, Baucus demurred, noting that "conferences are all fluid."

Other provisions in the bill could provide more harmony -- Boxer pointed to both chambers including language on a Gulf Coast oil spill recovery fund, and both sides have said the transportation policy provisions in the bill are closer than they may appear.

However, funding issues and length will dog the bill -- House Republicans would like to see a longer bill than the two-year version in the Senate and have proposed paying for it with domestic energy provisions, a non-starter in the Senate.

Reporter Manuel Quinones contributed.