A few years back, I wrote a column centered on an admittedly cheeky thought, that U.S. Sen. Bill Cassidy's 2020 reelection slogan could go something like this: “Bill Cassidy, protecting Mary Landrieu’s legacy since 2015.”

The legacy in question is a 2006 law called GOMESA, or the Gulf of Mexico Energy Security Act. Landrieu considered GOMESA her signature accomplishment, and Louisiana Democrats and Republicans alike welcomed its offshore revenue sharing arrangement, which provided dedicated funds for the state's vital coastal restoration efforts. She mentioned it often as she campaigned for a third term in 2014.

Yet that and other state-specific, nonpartisan accomplishments weren't nearly enough to protect Landrieu against Cassidy's main line of attack during that campaign, that as a Democrat she was out of touch with Louisiana's values. So when then-President Barack Obama's budget the following year proposed redirecting the GOMESA revenues away from the Gulf Coast and into broader environmental priorities, I couldn't help pointing out the irony in Cassidy's angry vow to block the move.

That wasn't meant as a criticism of his stance then, and it's not now. To Cassidy's credit, he took the same position when the Republican Trump administration floated a similar idea last year.

Stephanie Grace: Cassidy defending a Landrieu legacy

And even more to his credit, Cassidy used his position on the Senate Finance Committee to join with House Majority Whip Steve Scalise late last year to win Louisiana an even bigger share of offshore revenues.

There's actually a new irony here. The enhanced revenue comes from an amendment to the recent tax code overhaul, which was such a nakedly partisan effort that Landrieu herself probably wouldn't have backed it.

Still, the end result not only reinforces GOMESA's permanent benefit to Louisiana but also enhances its payouts just as they're finally scheduled to kick in. The amendment provides an additional $300 million in revenue from drilling at least 3 miles out for Gulf states. Louisiana, which gets the largest share, should receive at least $100 million of that, and all of the money will go toward fighting the scourge of coastal degradation, courtesy of a constitutional amendment that directs the money to restoration and hurricane protection efforts.

Given the breadth of the tax overhaul, which Republicans rushed through the process, this provision hasn't gotten much play.

Scalise has been busy on a grand media tour touting bonuses and raises that a few select businesses say they're giving due to the tax measure, in an apparent effort to change the widespread and entirely fair perception that, overall, the law is primarily a windfall for the rich. One recent news release carried the downright Trumpian headline, "I never get tired of winning." Another simply declared, "Laissez les bons temps rouler."

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Cassidy doesn't have as big a stage as Scalise does, but he too has been talking as much or more about the overall bill as about this particular piece of it.

Yet for the state that sent both men to Congress, this is a really big deal, a provision that will provide real long-term environmental benefits, protect infrastructure and support the coastal economy.

It's also a reminder of a somewhat outdated old truism that still holds. As nasty and overarching as party politics in Washington have become — and as effective as partisanship is as a campaign strategy, as Cassidy's victory over Landrieu proved — at least some politics is still local. 

Somewhere off in the private sector, Mary Landrieu is smiling. And she's not the only one.

Follow Stephanie Grace on Twitter, @stephgracela.