Elect a fraudster to the presidency — remember Trump University and the Trump Foundation? — and he will soon deliver a fraudulent budget. What makes this presidential fraudster’s first budget so special is the simultaneous perpetration of multiple levels of fraud.

Aside from defense spending, the Trump budget violates nearly every programmatic promise he made to voters last year. And he pretends to fulfill his promise of balancing the budget with fake numbers.

Not only are the numbers phony but also they represent the most audacious mathematical con game in a federal budget in recent memory.

It is phonier than the phony budgets cooked up during the Reagan era, when the president’s own budget director eventually confessed, “None of us really understands what’s going on with all these numbers.”

Trump’s numbers aren’t really so hard to understand. First, he projects an average 3 percent growth in gross domestic product over the next decade, which no sane economist of either party considers possible.

Then he estimates that this economic spurt will produce $2 trillion in federal revenues — and he counts those trillions twice in the same budget.

It’s hard to believe but true: The same $2 trillion is supposed to offset the Trump tax cuts that mostly benefit the wealthiest taxpayers, and to balance the budget over the next 10 years.

So Trump is pretending that his tax cuts will produce revenue growth instead of revenue deficits. And he is claiming that his pretend $2 trillion will somehow fill up a $4 trillion hole.

When reporters pointed out that this doesn’t add up as economics or arithmetic, White House budget director Mick Mulvaney amazingly affirmed that he had set down this double counting of trillions of dollars “on purpose.”

He went on to claim that the budget would work out anyway because its other calculations are so “conservative.”

Meanwhile, the details of Trump’s budget show in black-and-white just how coldly he swindled the voters who believed him last year.

At the big rallies where he basked in their adulation, Trump’s supporters heard him promise, again and again, that he would “save Medicare, Medicaid and Social Security, without cuts.” They heard him angrily accuse other Republican candidates of wanting to cut those popular, vital and successful programs.

They heard him vow to “solve the student loan crisis,” which was hurting their kids, because they “should not be asked to pay more on their loans than they can afford and the debt should not be an albatross around their necks for the rest of their lives.”

They heard him guarantee, in the most emotional terms, that their narcotics-addicted families, friends and neighbors, would receive “the top treatment” necessary to “get better.” They heard him swear to expand Medicaid treatment in communities ravaged by opioid addiction.

And they wildly applauded when he described a trillion-dollar infrastructure program to rebuild the nation and create millions of high-wage jobs.

According to the budget — grandly titled “A New Foundation For American Greatness” — those speeches were all hyperbole or, to put it less politely, a pack of lies.

There is in that document no sign of a trillion-dollar infrastructure plan, just the mindless observation that “simply providing more federal funding for infrastructure is not the solution.”

There is no expansion of treatment slots for opioid addiction, just massive cutbacks in all drug treatment and prevention programs.

There is no solution to the student-loan crisis, just the elimination of the entire federally subsidized student-loan program and the public service loan forgiveness program, which will make life worse for millions of young Americans.

There is no plan to protect Social Security or Medicaid, just nearly a trillion dollars in reductions in Medicaid funding that will cut off health care for at least 14 million low-income Americans, including children, and a steep cut in Social Security disability programs.

Of course there are mammoth tax cuts for the wealthiest fraction of one percent at the plutocratic top, the same people whose loopholes Trump promised to close.

Only a politician who thinks his supporters will never figure out how he scammed them would attempt such an epic betrayal. And perhaps that is the worst insult of all.

Joe Conason is editor in chief of NationalMemo.com. Click here to contact him, follow him on Twitter: @JoeConason, or click here to read previous columns. The opinions expressed are his own.