Among the biggest coups of Mary Landrieu's career in the U.S. Senate was passage of the Gulf of Mexico Energy Security Act of 2006, which required the federal government to split offshore oil royalties with Louisiana, Alabama, Texas and Mississippi.

Soon after that, voters approved a constitutional amendment putting Louisiana's share into a fund for hurricane protection and coastal restoration — clearly a wise move in the union's shrinkingest state.

Patience was required, however, for the act stipulated that the loot would not begin to flow until this year.

The standard measure of wetlands loss has long been the football field, and, according to the U.S. Geological Survey, our rate is one an hour. That means many arpents have disappeared while we waited for the act to take effect, but you can do the math.

Louisiana has been losing Democrats almost as fast as it has been losing coastal marshes, and Landrieu has taken the traditional path of former Congresspersons and gone into the lobbying racket. But if there is one issue assured of bipartisan support, it is offshore moola.

Indeed, Bill Cassidy, both when he was in the House and after he nabbed Landrieu's Senate seat, has filed legislation to increase the states' share. He vows he will continue to do so even as President Donald Trump's proposed budged envisages repeal of the Gulf Energy Security Act.

That would mean that, through 2027, the feds would razoo $3.6 billion currently due the four states. It would pretty much cripple Louisiana's coastal restoration program, and Trump's plan has been greeted with panic and alarm across Louisiana.

When Vice President Mike Pence visited Louisiana Wednesday, Gov. John Bel Edwards had a letter hand-delivered to him protesting both the proposed cuts to Medicaid and the elimination of offshore revenue sharing. Edwards pointed out that thwarting our efforts to halt the erosion of the coast “could have devastating economic effects across the entire country.”

While that point should be self-evident, it is in the long run that those economic effects will be felt, so Louisiana's sense of urgency may not be widely shared. As John Maynard Keynes famously observed, “In the long run, we are all dead.”

Perhaps it is premature for Louisiana to despair. President Barack Obama tried and failed to grab the states' share of offshore royalties, and nobody expects Trump's budget to make it through Congress.

On the other hand, one of the reasons such hawks as Sen. John McCain, R-Ariz, have declared Trump's budget dead on arrival is that they believe the military buildup it includes does not go far enough.

Under Trump's plan, various agencies would suffer savage cuts to make up for the $54 billion he wants shifted to defense next year. Any further splurge on weaponry might make the temptation of the offshore oil money impossible to resist.

Grabbing it would nevertheless undermine Trump's own energy strategy. He is keen to make the country more self-sufficient by selling off half the Strategic Petroleum Reserve and by inviting the oilmen to drill the Alaska National Wildlife Refuge. It would, as both Cassidy and Edwards have pointed out, be “shortsighted” to jeopardize production in the Gulf.

That would assuredly happen if the feds cut off the money Louisiana needs to keep its head above water. As Edwards put it in his letter to Pence, “The resources which must travel through the infrastructure networks in Louisiana require an ongoing federal funding commitment in order to maintain the environments and communities which make that possible.” There you have it in an elegant nutshell.

The loss of the money would leave the state's coastal restoration plan almost entirely dependent on proceeds from the settlement with BP over the massive oil spill in the Gulf. Even with the offshore royalties, it is hard to see how that plan will ever be funded. It costs $50 billion over 50 years, and we were $30 billion in the hole even before Trump proposed to administer the coup de grace.

Email James Gill at jgill@theadvocate.com.