What Mr. Trump has been particularly well positioned to do, though, is identify himself with economic success. He made his name as a celebrity tycoon. “It dovetails with a narrative about Donald Trump that has existed for a long time: that he’s a businessman, that he understands the working of the economy, that he knows how to make money,” said Mark Rozell, dean of the Schar School of Policy and Government of George Mason University in Virginia.

Mr. Obama’s background was in community organizing and the public sector. “No one expects such a person to have any feel for creating good economic conditions,” Mr. Rozell said. “He is more likely to be seen as riding an economic wave or trend, whereas the businessman is seen as responsible.”

Circumstances have also provided Mr. Trump with a tailwind. He has benefited from an additional year and a half of economic growth, which compounds the perception of the economy as resilient. The nine-year expansion has endured in the face of disruptions — from a global slowdown to trade tensions and unpredictable policy pronouncements.

Even if individuals are unaware of most details, the high confidence scores reflect the collective evidence and evaluations that the economy is hardy, said Tyler Cowen, an economist at George Mason University. “Markets aggregate information,” he said.

The extended recovery is naturally digging deeper. The Labor Department reported that joblessness fell to 3.9 percent in July, near the 18-year low it reached in May. The least educated workers — who have received the smallest share of the recovery’s rewards — were hired in greater numbers, while traditional industrial sectors like manufacturing that have suffered from decades of losses, added jobs.

Steep corporate tax cuts have raised longer-term worries about bloated deficits, and an anti-regulatory stance troubles watchdogs who warn that health and safety risks will increase. But in the short term, those actions have temporarily quickened the pace of growth, pumped money into the economy and buoyed business confidence.