President Donald Trump waves as he arrives to speak in support of Republican congressional candidate Rick Sacconne during a Make America Great Again rally in Moon Township, Pennsylvania, U.S., March 10, 2018.

Donald Trump believes in yesterday.

As a candidate, he gazed back at past glory with his "Make America Great Again" slogan. As president, he pursues an unlikely quest to push back historical tides in the economy and other realms of American life.

The most recent example is Trump's new tariffs, advanced to revive a shrunken steel industry. His rollback of environmental regulation seeks the same for the declining coal sector.

His pursuit of reduced immigration seeks to curb the number of foreign-born U.S. residents, which during his adult lifetime has swelled from 1 in 20 to 1 in 7. He likewise resists changes in gender relations, law enforcement, race and religion.

The president, who is 71, evinces little grasp of policy or philosophic conviction. But his impulses point in a clear direction: toward the very different America in which he came of age.

Trump turned 25 in 1971, the year he became president of his family's real estate business. Eight in 10 Americans were white Christians then. The American economy represented nearly 40 percent of global output.

Manufacturing employed one-fourth of the labor force. In a job market dominated by men, factory work still offered the promise of a middle-class living for those with only a high school degree.

Movements to protect women against domestic violence and sexual harassment had only begun to gain steam. Amid fears over rising crime, Clint Eastwood thrilled movie audiences as Dirty Harry, a tough-guy detective who disdained rules constraining police behavior.

The economic and cultural facts on the ground have changed dramatically since then. Trump's inclinations have not.

Stiffened international competition has sent the U.S. share of global output below 25 percent; manufacturing now employs fewer than 10 percent of American workers. Trump faults "bad trade deals" and seeks to renegotiate them.

As jobs in its trademark industry dwindled, the once-renowned "Steel City" of Pittsburgh has found new energy from service sectors such as education and health care. Unimpressed, Trump justified his tariffs before last month's special election outside Pittsburgh by insisting, "If you don't have steel, you don't have a country."

Trump complains that Canada, a potential tariff target, runs a trade surplus with the U.S. That's only true if the calculation excludes services — which now account for more than 80 percent of America's private sector jobs.

Withdrawing from the Paris climate deal, Trump invoked his love for coal miners. But coal's contribution to electric power generation has fallen to 30 percent from 50 percent over the last half-century. Renewable energy businesses, which benefit from the shift away from fossil fuels, employ far more workers.

Women represent nearly half of today's labor force – but just one-third of Trump administration hires, according to an analysis by The Atlantic. Despite a sweeping societal shift in attitudes, Trump has reflexively defended prominent men accused of sexual misconduct or domestic violence such as his former White House staff secretary Rob Porter. He faces multiple allegations of misconduct himself.

With white Christians now an American minority, Trump declares "Christmas is back" under his administration. Following a decadeslong drop in crime rates, Trump publicly urges rougher police tactics. His Justice Department has abandoned initiatives to improve police-community relations.

Trump rips athletes who protest law enforcement violence against blacks. He even mocks rules changes to protect football players which were made in response to mounting evidence that the game damages their brains.

Trump's predilection for throwback attitudes is not uniform. Though he grew up during the peak of the Cold War, he demonstrates a striking desire to improve relations with Russia. Moscow's interference on his behalf in the 2016 election is now under investigation by special counsel Robert Mueller.

Ominously for fellow Republicans, the public response Trump evokes after 14 months in the White House tracks his penchant for nostalgia. His strongest support comes from older white Christians and whites without college educations, especially men – large but shrinking segments of the electorate.

His strongest opposition comes from growing segments: nonwhites; college graduates, especially women; and millennials, the most racially and religiously diverse of American generations. Trump's candidate in that Pittsburgh-area special election lost – despite the steel tariffs and Trump's landslide 2016 win in the district.

A quarter century ago, Bill Clinton broke the GOP's grip on the presidency by modernizing the Democratic message to focus on the future. It was the polar opposite of Trump's approach.

Clinton's theme song in 1992 implored voters: "Don't stop thinking about tomorrow." Democrats have won the popular vote in six of seven presidential elections since.