In 1980 the US economy went into a recession. But that recession actually could have been predicted, if a very specific little line was taken into consideration. The yield curve has predicted every recession since the 1950s.
The strong economy is one of the key arguments the Trump campaign is using during its reelection efforts. There have been some recent news that suggest that not only is the economy slowing down, but the U.S. might be headed for a recession. If a recession hits before the 2020 election, the president will have an uphill climb to earn a second term.