Some years ago, while flipping idly through the channels on my TV, I stumbled upon a late-night vote on the U.S. Senate floor.

I have no idea what bill it was, or what year. What I remember was the scene. There were some of the nation’s most powerful politicians, milling about and casually chit-chatting in small groups.

And there was Mary Landrieu, scoping out the crowd, purposefully approaching and engaging key colleagues and, if memory serves, sometimes clutching their arms as if to keep them from backing away.

I couldn’t hear what they were saying but could certainly tell what was going on. They were ready to go home. She was still working. She was, frankly, making somewhat of a pest of herself, but she was doing it for the right reasons.

If I had to guess, I’d say this was late 2006, during the lame-duck session of the Republican-led Senate, as the Democrats were preparing to take over their new majority.

That’s when Landrieu was pushing to round up votes for a bill she co-authored with GOP Sen. Pete Domenici to finally provide Louisiana a share of revenue generated by expanded offshore oil and gas drilling, a bill that promised to direct as much as $650 million starting in 2017 to Louisiana for coastal restoration, according to estimates at the time. The bill, long a dream of state officials, was considered more likely to pass on the watch of pro-drilling Republicans then environmentalist Democrats.

But it could have been any number of occasions after hurricanes Katrina and Rita, when Landrieu led more efforts than I can possibly list to help individuals, institutions and localities recover. Or even after the BP spill, when she lobbied for a significant share of the fines to go to the affected states. She had help from her fellow Louisiana representatives, of course, but given her stature, key committee assignments and single-mindedness, Landrieu was the first among equals.

Those days are over, now that Landrieu is about to leave the Senate after 18 years of nights and fights like this. In truth, they were over even before she lost her bid for a fourth term to U.S. Rep. Bill Cassidy in a highly partisan election; that much was painfully clear during another big televised ballot, when Landrieu failed to muster a 60th vote to end a filibuster against the Keystone XL pipeline.

This one, unlike the others, wasn’t for the state but for her last-minute effort to win the December runoff, after her party had already suffered a rout in the general election. Many of her fellow senators came by to express sympathy, but they saw the writing on the wall and failed to give her one last win.

The truth is that, as Washington has become more polarized, Landrieu’s brand of state-focused politics has been going out of style. So when she offered more of the same to Louisiana voters last fall and asked them to swallow her votes with the Democrats and President Barack Obama along with her dogged advocacy, they took a pass.

Before she goes, it’s worth taking a moment to acknowledge how hard Landrieu worked, not for any big ideology but to meet Louisiana’s significant needs.

That’s what she was doing that night on TV.

It’s what she was doing when she took some of her most controversial actions. Like when she and her colleague David Vitter asked for $250 billion soon after Katrina, a request that prompted The Washington Post to label them “Louisiana’s Looters.” Or when she negotiated for a state-specific fix to a Medicaid reimbursement formula that was skewed by Katrina insurance payments during the battle over the Affordable Care Act. Conservative commentator Glenn Beck likened her to a prostitute for that one, even though Gov. Bobby Jindal wanted the fix.

In Louisiana, some local Republicans conceded that they would have been in dire straits without Landrieu’s help, although they mostly shied away from endorsing her re-election bid. Future governors, who are likely to be Republican for the foreseeable future, may not thank her for the millions in offshore and BP revenue, but they should.

In her final days, her Senate colleagues from both sides of the aisle — even Vitter, who played a major role in unseating her — lauded her commitment to her constituents, even as some of them winkingly noted that she could be a pain.

In talking about Katrina during her final speech, Landrieu did, too.

“I say to my colleagues: Thank you for being there for us,” she said.

“I know I aggravated you to death. I know I never stopped asking. But you were the only hope because there was just no way these communities could recover.”

But she didn’t apologize. After 18 years of fighting for her beloved Louisiana, Landrieu has nothing to apologize for.

Stephanie Grace can be contacted at sgrace@theadvocate.com. Read her blog at http://blogs.theadvocate.com/gracenotes. Follow her on Twitter, @stephgracenola.