When your main campaign sales pitch is based on your “clout,” and you lose the basis of that clout, then your campaign is probably a goner. For that and other reasons, U.S. Sen. Mary Landrieu has almost no remaining path to re-election.

Landrieu’s self-proclaimed clout as chairwoman of the Senate Committee on Energy always was rather illusory. Now, with Republicans running the Senate and a Democratic president wholly antagonistic to Louisiana economic interests, Democratic loyalist Landrieu will be doubly blocked from influence on behalf of the state.

Landrieu will keep trying to “localize” the election by ginning up irrelevant issues on subjects she’ll have little power to influence anyway. (Hint: If she couldn’t get President Barack Obama to lift the offshore “permitorium” when Democrats controlled the Senate, she surely won’t be able to get a lame-duck Obama’s ear now.) The truth, however, is that the U.S. Senate deals mostly with national issues. On those, Landrieu is out of step with a state she said is both too bigoted to give a black president a chance and too “conservative” to support strong women, herself presumably included.

Landrieu always claims to be a centrist ­— but the National Journal, the respected, neutral magazine that covers American government in depth, reported this year that the very existence of centrists in the Senate is “all but gone.” Even for that nearly nonexistent center, Landrieu wouldn’t qualify: In a decidedly liberal Democratic Senate caucus, reports National Journal, 10 other Democrats are less liberal than she.

Here’s one example. Through what a judge called “grotesque” misconduct, the Civil Rights Division of the Obama Justice Department already royally bungled the prosecution of the Danziger Bridge police officers; Landrieu voted to make that division even more radically leftist by supporting a nominee to head the office, Debo Adegbile, who went out of his way to wave the race card while arguing to overthrow the conviction of notorious cop killer Mumia Abu-Jamal. Fortunately, the nomination failed anyway, with seven Democrats (but not Landrieu) helping block Obama’s awful selection.

(Landrieu wouldn’t give the same consideration to manifestly qualified Bush judicial nominee Miguel Estrada, even after pledging to local Latinos that she would support him.)

Louisianans chafing over the loss of free checking accounts, meanwhile, can blame Landrieu for casting a crucial vote in favor of the Dodd-Frank regulatory scheme which is leading banks to wipe out such accounts and otherwise hurting low-income customers.

Perhaps Landrieu’s most appalling vote came when she refused to join Republicans and 32 other Senate Democrats to repeal “Obamacare’s” horrendous tax on medical devices such as pacemakers, insulin pumps, vascular stents, MRI machines, cardiac defibrillators and even dentures ­— a tax not only hampering development of life-saving products, but also already eliminating thousands of jobs nationwide. Frankly, this vote — cravenly following Obama’s line, even when large Senate majorities of both parties were willing to buck the president — was unconscionable.

Granted, no fair-minded person would argue that Landrieu hasn’t “delivered” some good things for Louisiana, or that she hasn’t worked hard for 35 long years in public office. But, other than trading her key vote for “Obamacare” in return for the so-called “Louisiana Purchase,” she hasn’t been able to do much for the state, legislatively, since Obama took office.

As it is, Landrieu now faces arithmetically huge odds to win re-election. She and Rep. Bill Cassidy finished in a near dead-heat in the open primary with just over 600,000 votes each, with conservative Republican Rob Maness taking another 200,000 votes. Even if some of Maness’ voters stay home in December, and even if Landrieu somehow inspires more Louisianans to turn out for her than did last Tuesday, it’s still hard to figure how she can make up Tuesday’s overall Republican margin of 180,000 votes.

Pundits on both the right and left even say Landrieu should drop out, rather than trying a scorched-earth campaign that still would fall short, while damaging the Landrieu political brand. It worked in 1987-91 for Edwin Edwards, who regained the governor’s mansion just four years after declining to contest a runoff. Landrieu has far more to offer than Edwards did — as long as she doesn’t poison the well through a nasty, probably hopeless campaign.

New Orleans native Quin Hillyer is a contributing editor for National Review. You can follow him on Twitter, @QuinHillyer. His email address is qhillyer@theadvocate.com, and he blogs at blogs.theadvocate.com/quin-essential.

Editor's Note: This column was updated at 11:25 a.m. on Nov. 12, 2014, to clarify wording in the last paragraph.