It might be hard to imagine, but in many ways the US was in worse condition in 1979 then it is today. Carter was a complete bungler, in way over his head. The economy was so bad they had to invent a new word to describe it, "stagflation". Endless inflation with no growth.
Carter's response to the situation was to blame the American people. He said they suffered from a "malaise". Of course, the malaise was a lack of leadership. His leadership.
But his economic disaster paled in comparison to his foreign policy mistakes. Carter engineered the fall of the Shah of Iran, and ushered in the rule of the mullahs. The mullahs declared war on America by seizing the US embassy and holding its occupants hostage. Carter was helpless and hopeless as he himself became a hostage in the White House. Meanwhile the daily hostage drama was played out endlessly on all three networks.
And then came Reagan. Reagan ran an optimistic campaign. He promised to get the hostages out, revamp the economy, and make America mighty again. He kept his promises and more. His very election ensured that the hostages would be released. No one alive at the time can forget the split screen of Reagan being inaugurated and the plane full of hostages lifting off from Tehran.
Sorry, I got carried away to a time when America was feared by its enemies and loved and respected by its allies. Good times.
Yes, Reagan was considered a lightweight by the cognoscenti. Despite more achievements than any other 20th century president he was not taken seriously before, during, or after his presidency by most of the punditocracy. Trump is no Reagan, but there are many many similarities.