It is, the president tells us with his penchant for personal aggrandizement, “the biggest and boldest infrastructure program in American history” — a $1.5 trillion plan to rebuild and repair the nation’s crumbling highways and bridges.

But the devil is in the details: He conveniently managed not to say that only about $200 billion would be federal funding, which would be spread over a 10-year period, and that state/municipal governments and private sector funding would be expected to pick up the tab for the balance.

Yeah, right. Most state and local governments are so cash-strapped now that coming up with a collective $1.3 trillion is about as likely as snow in the Mojave Desert in the middle of August.

Correctly terming the condition of the nation’s infrastructure “horrendous,” the president said his plan will “generate” a $1.5 trillion to $1.7 trillion investment. But there’s a world of difference in “generate” and actually putting up cash to get the job done.

Congress has consistently chickened out on raising the federal gas tax, the chief source of money for the Federal Highway Trust Fund — money that has been sharply and consistently declining as vehicles become more fuel-efficient. The tax hasn’t been increased in a quarter century.

Previously, federal infrastructure programs have generally been on a 50/50 or 80/20 federal/state basis. The president’s proposal would make that 80 percent state/local and only 20 percent federal. And in a one-hand-giveth-the-other-taketh-away move, his federal budget proposal would slash some $280 billion from infrastructure funding.

Oh, and while he’s at it, he would cut billions from farm/conservation/forestry programs, and crop insurance, not to mention peddling off D.C’s two ultra-busy airports, Reagan and Dulles. And the Tennessee Valley Authority generation system and electrical grid, a linchpin of progress for the rural South and Appalachia since the Great Depression — well, he opines, it would better meet the electricity needs of the region if privately owned.

Those urgently needed new roads and bridges, in many cases, would be opened to private investors. Can you say toll roads/bridges/tunnels? Ask Floridians (No. 1 state for toll roads) or Texans (No. 5) who have to fork over a toll every few miles on some of the state’s major freeways how much they like that extra cost. And private investors would cherry pick projects with the most profit potential, while ignoring the needs of less populated, less profitable rural areas.

Congress has consistently chickened out on raising the federal gas tax, the chief source of money for the Federal Highway Trust Fund — money that has been sharply and consistently declining as vehicles become more fuel-efficient. The tax hasn’t been increased in a quarter century. Many states have been similarly kick-the-can-down-the-road about boosting the gas tax or finding other ways to pay for roads and bridges — in my state, Mississippi, the gas tax hasn’t been increased in more than 30 years and this year’s legislature has danced around that once again, proposing instead a convoluted financing plan that only Rube Goldberg could love.

The president’s grand plan for infrastructure is probably dead on arrival in Congress, and in an election year Congress isn’t likely to pass anything that smacks of a tax or that involves major federal expenditures (unless it’s for the military).

And the nation’s infrastructure, rated D-plus in 2017 by the American Society of Civil Engineers, will only continue to deteriorate.