Getting one quarter of breakout economic growth is easy: Presidents Barack Obama and George W. Bush did so on multiple occasions, only to see things fall back into the same pattern soon after.

Sustaining that level is the hard part, something no president has accomplished since Bill Clinton. With some of the biggest factors boosting second-quarter growth expected to fade over time, President Donald Trump will have his work cut out for him.

But that doesn't mean he can't get it done.

"These numbers are very, very sustainable. This isn't a one-time shot," Trump said in an appearance after the Commerce Department reported Friday that GDP rose 4.1 percent in the April-to-June period. "I happen to think we're going to do extraordinarily well in our next report, next quarter. I think it's going to be outstanding.

"I won't go too strong, because then if it's not quite as good you'll not let me forget it."

Indeed, all eyes on Wall Street and Main Street will be watching to see whether the above-trend gains can last.

For the U.S. economy, the most recent period marked the best performance since the third quarter of 2014, when the economy grew by 4.9 percent, coming off 5.1 percent in the previous period. But those growth periods were marked by a burst in government spending that would not last — the economy enjoyed a few more decent quarters before falling off to a 1 percent growth rate in the third quarter of 2015, and would not exceed 3 percent until the most recent reading.

In short, the hot take from most economists is that an above-4 percent rate isn't sustainable. But that doesn't mean the U.S. can't enjoy a lasting period of growth that will justify at least some of the Trump administration's enthusiasm about the path ahead.