Instead of enjoying anything close to overwhelming popularity because of the economy, Mr. Trump’s national approval rating has remained low, dropping about two percentage points to 41 percent since the Ukraine story broke. One problem with Mr. Trump’s campaign message is that the economic expansion started before the president assumed office, causing many voters to take it for granted.

“At this point, voters may think this is just the normal economy,” Mr. Fratto said. “That gives them the luxury to focus on other things, like the behavior of the president.”

Another factor is also at play: While Mr. Trump routinely talks up the economy, he is far more passionate when lashing out at Democrats over the impeachment inquiry, or simply riffing about the news of the day, than when discussing the stock market and unemployment rate. His off-the-cuff comments often overshadow his dutiful recitations of gains.

At the White House on Friday, Mr. Trump noted in a monotone voice that the unemployment rate was “at the lowest rate, as I told you, in many years and in many ways I think we probably very soon say historically.”

He only seemed to come alive when discussing rolling back energy standards on light bulbs. “The new bulb is many times more expensive and I hate to say it, it doesn’t make you look as good. Of course, because being a vain person that’s very important to me,” he said, noting that it “gives you an orange look.”

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Mr. Trump’s penchant for steering the conversation away from the economy is frustrating for many Republicans and business leaders, given America is powering through a record 11-year expansion. Employers have hired 2.2 million people over the past 12 months, a surprisingly robust performance at a time when unemployment is at 3.5 percent — its lowest in half a century.

Those gains have often come in spite of Mr. Trump’s policies, not because of them. And it remains an open question how long the pace of growth can continue.