Susan Davis and Deborah Barfield Berry, 11/14/14 | www.usatoday.com

WASHINGTON — Republicans in the U.S. House approved legislation, 252-161, for the ninth time to authorize construction of the controversial Keystone XL oil pipeline in a legislative push renewed by two lawmakers locked in a Louisiana Senate runoff next month.

"This will create other economic activity. This will ripple out through the economy," said GOP Rep. Bill Cassidy, the sponsor of the House bill. Cassidy is favored to oust incumbent Democratic Sen. Mary Landrieu in a Dec. 6 runoff election necessary because neither surpassed Louisiana's 50% threshold on Election Day.

Landrieu is a co-sponsor of the Senate bill and sparked the renewed push for the pipeline earlier this week with the help of other centrist Democrats from conservative states who also back the pipeline despite opposition from most Democrats.

Cassidy said "of course'' the House vote helps his campaign efforts. There's an ad running in Louisiana now "talking about how passionate I am about creating energy jobs. And so the timing of this could not be better.''

The Senate is expected to vote Tuesday on the bill. If it overcomes a 60-vote threshold it will head to President Obama's desk where he will either sign it into law or veto it. The president has delayed a decision on the pipeline, deferring to an ongoing review at the State Department, but White House spokesman Josh Earnest suggested Thursday that the president could veto it.

The president is under pressure from environmental groups who oppose the pipeline. Republicans counter that the pipeline's construction would produce jobs. The six-year delay has not slowed oil production by TransCanada, but it has made transporting it to refineries on the Gulf Coast more complicated.

"Understand what this project is: It is providing the ability of Canada to pump their oil, send it through our land, down to the Gulf, where it will be sold everywhere else. It doesn't have an impact on US gas prices," said Obama, who is travelling in Asia. "If my Republican friends really want to focus on what's good for the American people in terms of job creation and lower energy costs, we should be engaging in a conversation about what are we doing to produce even more homegrown energy. I'm happy to have that conversation."

The pipeline has been consistently supported in the GOP House but delayed in a Democratic-controlled Senate because of the 60-vote hurdle. Landrieu is optimistic she can get the votes this time, in part because the party is hoping she can pull off a long-shot victory. Failure to pass Keystone would undermine her argument that she is more effective for her state's oil and gas industry than her GOP opponent.

"We're going to make sure that the senator is delivering the votes," said Ryan Berni,Landrieu's campaign manager, noting that Cassidy's bill is mirror legislation to the Senate proposal. "This is really not about what Bill Cassidy has done in the House, but about the senator being able to bring both parties together to get a vote on something that has bipartisan support and is actually popular and really set it up as her ability to deliver both parties to get something done that is fairly common sense."

Landrieu's co-sponsor, Sen. John Hoeven, R-N.D., said that if Democrats fail Tuesday, the pipeline is assured passage when Republicans take control of the chamber next year. "All along, we anticipated that we'll win on this issue, because the American public wants Keystone XL approved," he said, "If we don't get 60 votes on Tuesday, in the new Congress, we will have 60 votes."

Republicans will control at least 53 Senate seats next year. If Cassidy defeats Landrieu, they will have 54 seats. At least six Democrats returning to the Senate next year support the pipeline.

Contributing: David Jackson