By the time Barack Obama arrived at the White House, 31/2 years had passed since the notorious 2005 hurricane season, when Louisiana was assaulted by two of the nine costliest Atlantic storms in recorded history.

America had pretty much moved on, as the nation struggled with a deep and frightening recession and two wars that seemed like they might never end.

So some worried that the new administration might forget our struggles. But Barack Obama proved to be a friend to Louisiana, rebuilding public housing in New Orleans and settling long-standing disputes in a way that enabled New Orleans and Louisiana to find bold and imaginative ways to replace public schools and our flagship public hospital.

Which is why it is so disappointing to see a president who has been an ally turn against our state at a critical moment in the fight to save our vulnerable coastline.

In 2006, with the memory of the storms still fresh, Congress passed the Gulf of Mexico Energy Security Act, which directed a share of revenue from drilling in federal waters to Louisiana and three other Gulf states. The measure passed overwhelmingly, though it was opposed by Obama, then a senator from Illinois.

Louisiana, Texas, Mississippi and Alabama have shared in about $30 million a year from GOMESA, chiefly revenue from the eastern Gulf. But starting in 2018, revenue from the far more productive central Gulf will come under the law. The formula caps the total share for all four states at $500 million annually, but the sum may be smaller if energy prices stay low.

For a decade, Louisiana has been counting on that revenue to finance the fight against coastal land loss, which claims a football field every hour. The effects of that land loss were starkly clear on August 29, 2005, when Hurricane Katrina attacked southeast Louisiana, levees and floodwalls gave way and four-fifths of New Orleans was underwater.

In 2012, the state approved a coastal master plan that envisions spending $50 billion over 50 years for protection and restoration, and the GOMESA funding was a vital piece of that.

But the president proposes to take the money away from the Gulf Coast states and “redirect the distribution of expanded revenue payments ... to programs with broad natural resource, watershed and conservation benefits for the entire nation.”

Today, Barack Obama is visiting New Orleans, perhaps for the final time as president.

He will find a community that has rebuilt itself with creativity and commitment, helped along by support from the nation and from his administration.

New Orleans is safer than ever, protected by giant works of earth and concrete. But Louisiana is more vulnerable every day, as the wetlands that shield our state vanish into the sea.

The work of rebuilding New Orleans has gone on for a decade now, but the work of rebuilding Louisiana has hardly begun. We need the federal government to be a supportive partner in that effort, and that means honoring the deal that was approved in Washington in 2006. The task of persuading Barack Obama to keep Washington’s promise falls to everyone who meets with the president today.