In November of 1980 a manifestly unfit man defeated a weak Democratic presidential opponent. This actor at least had some political experience, but largely he was known for his reactionary views, adoration of the past, racial insensitivity, and devotion to American supremacy. I wore a black armband for the inauguration, assured that disaster was soon to follow.
Reagan gave us (in no particular order):
- threats to bomb Russia that appeared serious. By 1983 I was convinced we were more likely than not to die in a nuclear holocaust; the Doomsday Clock stood at nearly midnight. When Sting wrote Russians he was speaking for millions of us.
- Iran-Contra. In case you've forgotten, that's where we illegally sold weapons to Iran in order to fund drug-running paramilitaries in Nicaragua that were guilty of (among other things) executing priests in front of their congregations. We also mined harbors and taught these narco-terrorists how to torture civilians. 
- Actual military invasions of three different countries. 
- More sitting Cabinet members indicted than any other administration in modern history, not least of them the most corrupt Attorney General on record.
- The Savings & Loan scandal and the first housing-market collapse.
- The Reagan Recession, featuring 10% unemployment and a sharp rise in income inequality, caused by (among other things) an insane set of supply-side policies that came to be called "trickle-down" economics.
- a refusal even to say the word "AIDS" never mind treat gay men as human beings, leading to the deaths of dozens of my acquaintances and a couple friends.
I am insanely lucky. I am an older white man, well-off. I can ride this out. I can definitively say that there are other older white guys who are in even worse shape today than I am (Paul Ryan comes to mind). There are people who are genuinely going to suffer in the next four years for whom I have true sympathy - immigrants, Latinx, and so on. I fear for my friends who are likely to find their marriage equality stolen from them and for millions who are about to lose their health insurance. I believe we'll almost certainly finish fucking up the planet, causing irreversible warming, and our children will rightly curse us for that.
The next four years are nohow going to be good, nor easy. But we survived eight years of Reagan, we can survive this. None of the above means I'm not having anxiety that wakes me up multiple times a night. But one of the advantages of being my age is that you have some past experiences to compare things against. I'm sorry for my friends who find President Trump a de novo catastrophe. Having a Republican Congress is certainly going to make him capable of far more damage, and we're going to be in even bigger trouble if he gets a second SCOTUS appointment, which I think is highly likely. But we'll survive it.
And in a couple decades they'll decide he was a great president and name an airport for him.
 There's also good evidence that as part of this effort the US Government gave sanctuary to Central American drug kingpins and facilitated the flow of crack cocaine, which would make the Reagan Administration responsible for even more deaths than AIDS, but I have to stop somewhere.
 You can also argue that Reagan was the true father of the Taliban and from that ISIS since his administration trained, armed, and funded anti-Russian paramilitaries including Osama bin Laden and his ilk.