By Doyle McManus

Los Angeles Times

In 1976, 10 presidential terms ago, an advisor to then-President-elect Jimmy Carter told him he should keep campaigning forever, even after his inauguration.

“Governing with public approval requires a continuing political campaign,” Patrick Caddell told Carter. The doctrine became known as “the permanent campaign,” and every president since has followed it.

President Trump has now extended the principle even further than his predecessors: He seems to think “permanent” means “constant.”

Most new presidents use their inauguration to move forward, appeal to opponents for a joint effort at unity, and set some clear goals for the next four years.

Not Trump. He’s still stumping. After stretching his campaign past Election Day with a series of raucous victory rallies, he gave an inaugural address on Friday that replicated, in only slightly more elevated language, the pitch that helped him win the presidency.

His speech reprised all the themes that built a successful insurgency among mostly white, mostly middle class voters. He didn’t say or do much, if anything, to try to expand his coalition. There was no explicit outreach to the majority of voters who didn’t choose him in November. Most important, he didn’t signal how he plans to get anything done.

That’s a problem. A permanent campaign can help a president bolster his base of support, but it’s not enough to enable him to achieve his goals.

And Trump has promised the world.

“America will start winning again, winning like never before,” he said Friday. “We will bring back our jobs. We will bring back our borders. We will bring back our wealth. … We will build new roads and highways and bridges and airports and tunnels and railways all across our wonderful nation. We will get our people off of welfare and back to work.”

He also said he’d rid the country of crime, gangs and drugs: “This American carnage stops right here … right now.” As for the threat of Islamic terrorism, he vowed to “eradicate (it) completely from the face of the earth.”

Ask Trump voters what they want him to do, as I have since the election, and they often begin with: “Keep his promises.”

“I want him to improve the economy, bring back jobs,” Matthew Szramoski of Lorton, Va., told me as he waited on the Washington Mall for the inaugural ceremony Friday morning. “Do something about illegal immigration, build a wall.”

“Healthcare,” added a woman who didn’t want to give her name. “He’s promised to fix healthcare.”

Some of Trump’s pledges are simply unrealistic. He’s not going to eliminate crime or drugs. He might succeed in suppressing Islamic terrorism (although he hasn’t spelled out a strategy), but he’s unlikely to “eradicate” it.

Even his top ambition of bringing back jobs — especially in manufacturing, steel and coal-mining — will be difficult.

His economic program, outlined without much detail on his new White House website, relies on tax cuts (especially for the wealthy), deregulation (especially for coal and other energy industries), and renegotiated trade agreements.

It’s not clear, however, that higher trade barriers will do much to increase manufacturing employment, which economists say has fallen mostly because of automation.

And there’s nothing at all on the website about Trump’s vaunted infrastructure program — perhaps because there’s a divide in his administration on how to pay for it. Trump’s economic advisors have proposed a modest plan that would use tax credits to subsidize for-profit toll roads and bridges; his advisor Stephen K. Bannon, who helped write the inaugural address, has called for something bigger, broader and more expensive.

That divide between traditional Republicans and populists could get in the way of fulfilling some of Trump’s other promises too. Trump says he wants to replace President Obama’s healthcare plan with a system that covers at least as many people at lower cost; most conservatives don’t want to spend the money that would require. Trump says he wants to protect Social Security and Medicare from cuts; conservatives are eager to trim those entitlements.

“Now arrives the hour of action,” Trump said. “Do not allow anyone to tell you that it cannot be done. … We will not fail.”

The new president will continue to campaign, because that’s what he knows how to do, and he’s good at it.

But at some point he needs to deliver. Just ask Jimmy Carter.

Doyle McManus is a columnist for the Los Angeles Times. Readers may send him email at doyle.mcmanus@latimes.com