The military industrial complex literally sabotaged the Iran hostage negotiations in order to drag it out to cost Carter the White House, just to make sure they would get some tax cuts in the next administration.
Meanwhile, Trump has the conservative rage media machine operating 24 hours a day, 7 days a week, 365 days a year, with an unlimited budget and a never-ending Army of Internet trolls who are either evil enough to say anything or dumb enough to believe anything. He also has the literal KGB (FSB) looking out for him with a steady stream of free money, intelligence, and all manner of honeypotting, extortion schemes, and outright violence. Trump has Fox News and Twitter literally tripping over themselves to try and make sure he wins. Fox spent $787 million to settle a lawsuit so they could lie their asses off for Trump. Carter never had help anywhere even close to that.
I wasn’t there, but my understanding is that Reagan was much more of a populist while Carter tried to be more evidence-based and treat the electorate like rational adults (which is generally a terrible idea for a politician)
I was around: it was a depressing time (and I even liked Carter):
• The Iran hostage situation was ever-present. It was nightly news, to the point that all the major broadcasts started out with “this is day #X of the hostage situation”.
• Carter tried to rescue the hostages, and failed badly - 8 servicemen died, and this was just a few months before the election.
• Carter pissed off a lot of people by boycotting the 1980 Olympics (boycotting USSR’s invasion of Afghanistan - Ironic in that the US eventually did 20 as well years later). Lots of atheletes spoke out, their only or last time to make it to the Olympics. Turning the Olympics into a political weapon left a bad taste in general.
• Inflation rates were incredibly high, I think 12%-ish.
• Housing interest was through the roof, heading towards 13% (it eventually hit 18% under Reagan, I think)
• We were in the beginnings of a severe recession.
• Carter was never very charismatic - he was smart guy, but gave pretty boring speeches (IMO)
And then you have Reagan show up… optimistic, charismatic, and people just wanted change.
As fucked up as the economy is right now, it doesn’t hold a candle to the 70s. People freak about 7% mortgage rates right now, they started there in the 70s and went up to 13%-ish by the time Reagan was elected. The shit show started under Nixon, but people seem to blame Carter. Probably because of the time he had the audacity to ask Americans to turn their thermostats down. (I was just a bit too young for all this, so this is all filtered through what my parents told me.)
Combine that with the Iran hostage crisis, and the fact that Carter was too honest for his own good, and he didn’t stand a chance in 1980 against a charismatic opponent who wasn’t afraid to bend the truth now and then.
I found this link to a good overview of it all. It seems to be part of some course (there is a quiz at the end)