— Mary Landrieu’s Keystone pipeline gambit pretty much played out, as the headline writers put it, as a “hail Mary” pass — a desperate attempt, with the clock running out and the score against her, to change the outcome of the game.

Its denouement as a “fail Mary” is probably less significant than the fact that she tried it at all.

The game in this case is Landrieu’s attempt to win re-election to the U.S. Senate. A Democrat, she was challenged by two well-financed Republicans in the Nov. 4 open primary: U.S. Rep. Bill Cassidy, of Baton Rouge, the anointed candidate of the Republican establishment, and political newcomer Rob Maness, of Madisonville, who ran with tea party support.

Landrieu finished first, with 42 percent of the vote, but barely ahead of Cassidy. As a three-term incumbent and the only legitimate Democrat in the field, her showing was dismal.

The combined Republican vote, for Cassidy, Maness and a minor candidate, totaled 56 percent, reflecting the red wave that swept the country and carried Republican candidates for Congress to victory after victory. And the Republicans reached their high-water mark in the Deep South: Landrieu is the last white Democrat from the region with even a chance to serve in the next Congress.

Upon consideration of the Nov. 4 returns and polls indicating Cassidy would beat her in a runoff, Landrieu apparently decided that her chances on Dec. 6 are very slim. So she dropped back and heaved a bill to greenlight the pipeline onto the Senate floor.

Landrieu’s act took center stage in the political media. As events showed, the outcome was uncertain. What’s more certain is that no candidate figuring on anything close to an even shot at winning election would risk such a highly public failure.

And it’s far from clear that success would have moved the needle much for Landrieu in Louisiana. The bill would have required Democratic President Barack Obama to approve the final, northern section of the pipeline, to transport “dirty” tar-sands oil from Canada to refineries on the Texas Gulf Coast.

Supporters of the pipeline say it will create jobs and reduce American dependence on oil imported from unstable foreign countries outside North America. Opponents fear it will result in increased carbon emissions, and the project has been stalled by Obama, whose approval is required because the pipeline crosses an international border.

But even Landrieu has acknowledged the debate is largely symbolic.

The pipeline would create only a few dozen permanent jobs, and the thousands of temporary construction jobs it would support would be hundreds of miles from Louisiana. Much of the oil the line delivers likely would be exported.

On the other side, the U.S. State Department has said any environmental impact would be minimal — in large part because even if the pipeline isn’t built, the oil probably will be shipped to market by some other means.

Plus, Obama strongly indicated that if the bill passed, he would veto it, with no chance for an override before the current Congress shuts down at the end of the year.

Nonetheless, the bill spurred a lively debate on the Senate floor, stretching over six hours. But the best line may have been delivered by Landrieu in a quickly assembled news conference after the proposal was defeated.

Landrieu needed 15 Democratic votes to combine with the solid Republican minority to reach the threshold required for approval. She got 14 and was asked if she blamed lobbying by the White House or others for the setback.

“Well, first of all, there is no blame,” she said. “There is only joy in the fight.”

Pretty much pure Landrieu. She clearly relishes the political life, whether in the Senate or in the campaign — assisting at a keg stand outside Tiger Stadium, or doing the “Wobble” at a Southern University tailgating party. And by all accounts, she’s not afraid to mix it up and get after it.

Cassidy has his virtues: He’s an intelligent guy with a wide-ranging intellectual curiosity and a demonstrated commitment to the health and welfare of the community (a doctor, he opened a free clinic in an abandoned Baton Rouge Kmart for Hurricane Katrina victims, among other good works).

But it’s hard to imagine him proclaiming, “There is only joy in the fight.”

Follow Gregory Roberts of The Advocate Washington bureau on Twitter, @GregRobertsDC.