Look at 1996. Bill Clinton ran against the utterly boring Bob Dole in a time when the economy was booming, things were great and prosperous, the GOP were seen as crybabies due to the 95-96 government shutdown, and he still didn't crack 50% of the popular vote. Yes, a part of that can be blamed on Ross Perot's second run, but even without Ross Perot, this wouldn't have been any landslide, which, considering the circumstances and opposition, it should have been. If you read any Clinton biography, in terms of polls, most Americans either didn't trust him or viewed him as unethical at the time. I wonder if that factored into his narrow victory?
52% of Americans had an overall negative view of the economy in 1996, which probably made a difference.