To decipher President Donald Trump’s presidency, apply the basic rule of politics: Follow the money.

Last month, for example, Trump performed at rallies in North Carolina and in New Mexico. He entertained adoring crowds, clad in Trump’s MAGA caps and T-shirts.

The rallies got featured on Fox and other news stations.

Then Trump flew to California and went to a series of big-dollar fundraisers that were closed to the public, pocketing what his campaign boasted as more than $15 million in campaign funding, largely from anonymous wealthy donors.

This is only a small part of the record campaign war chest that the wealthy are building for Trump’s re-election campaign.

The press treats the overwhelmingly white, working class audiences at Trump’s rallies as his “base.” But they are more his marks than his base. The anonymous wealthy donors in California have a far better claim to be the base that he serves.

The donors got the tax cuts; the working people at his rallies got health care cuts. The CEOs got the roll-back of clean water and clean air regulations; his rally audiences got the fouled water and more kids with emphysema.

Big oil and coal executives got lavish public subsidies; teachers and parents got cuts in school funding. Big Agra got billions in payoffs to make up for Trump’s trade war; family farmers were casualties, many bankrupted by the loss of markets, with Wisconsin’s small farmers suffering the worst.

Auto executives enjoyed record profits; auto workers suffered more layoffs and plant closings. The rich saw their wealth soar; working people faced rising prices in housing, health care, college, cars — with incomes that didn’t keep up.

Trump brags on the record-low unemployment numbers, but the jobs too often don’t pay a living wage and Trump and Republicans won’t even allow a vote on raising the minimum wage.

Not surprisingly, workers are beginning to protest.

GM autoworkers are involved in the largest strike in years. Teachers in red states across the country have gone on strike to demand greater investment in schools. Nurses are on strike for decent wages and better staffing of hospitals and clinics.

Fast food and restaurant workers have led marches for a $15 minimum wage and a union. Young people are marching to protest Trump’s refusal to address the clear and present threat posed by catastrophic climate change.

Trump regales the crowds at his rallies with scurrilous attacks on his opponents, lies and tales about his accomplishments, and boasts about the economy. He panders to their fears, fanning racial division, railing against immigrants and Muslims and the homeless.

He’s pugnacious, funny and outrageous. They know he’s a bad guy, but they think he’s their bad guy. And that is the con.

The anonymous donors who are contributing record amounts to Trump’s campaign don’t wear MAGA hats. They don’t go to public rallies.

They roll their eyes at Trump’s rambling rants and racial taunts. They aren’t on strike or in the streets. They are getting a great return on their investment and are happy to ante up again.

The Trump economy doesn’t work for most Americans, but it works for them. Trump keeps his promises — and his payoffs — to them.

They know Trump is a grifter, but he’s their grifter. They are all in on the con.