In short, it was a good book. I highly recommend it. No, you don't have to like horror, because it really isn't horror. No, you don't have to like SF, because that is such a tiny bit of the story it doesn't matter. Sure, you have to suspend belief a little bit, but don't you have to every time you read a novel?
It's a story of what would happen if a small town was suddenly cut off from from the rest of the world. I know, that doesn't sound so exciting. Now, throw in the fact that the guy in charge of the town is a fool and is actually just a figure head and the second in charge is really the man running the show. Also, some not so legal things are going on in town and said things are being run by the people in charge of the town. Also, the second in charge is a power hungry man who decides that the dome is a good thing for him. This is why things get interesting.
The real man in charge is "Big" Jim Rennie. Local car dealer, religious man, who always looks out for the best of the town while making sure his secret illegal operation is making him rich. After the dome comes down the town police chief (Big Jim's mortal enemy) dies, allowing the man Big Jim trusts to become the chief. Which leads to Big Jim filling the officer ranks with people that will do anything he says, and not really follow the code of conduct one would expect a police officer to follow. Basically the town is eventually under martial law with Big Jim as the dictator. All for the good of the people of course. Not to mention that this is set into motion based on a small riot set up by Big Jim himself. Yes, he is kid of a dick. You really get to hate him. This is what King does well. He can really flesh out a character so much that you know if you met this guy in real life you'd want to punch him.
On the other side we have Dale Barbara, Barbie to his friends. Baaaarbie to is enemies. We meet Barbie as he's trying to leave town after a confrontation with Big Jim's son. He's on the Rennie's shit list and knows it's best to get out of town. He almost makes it out of town before the dome comes down, but instead he's at the edge of town when the dome clamps down on the town. He sees a woodchuck cut in half and a small plane crash into it. He knows this isn't going to be a good situation. He's right.
It turns out nothing can bring the dome down. The US Army tries several things but nothing works. This doesn't help the stability of the town. Nor, do the actions of Big Jim. Eventually, the town starts getting split up into two factions. Those against Big Jim and his cronies in the police department, and those for. But, due to some tactics by Jim and his police, the side against him is much smaller. He knows how to play to the towns people's fears.
The President tries to put Barbie in charge by executive order, but Big Jim gets Barbie locked up on some false murder charges. That sets into motion the climax which includes a jail break and some bad stuff that I don't want to describe here and give away. It wasn't unexpected, but the scale was larger than I expected.
Like I said before, this is one of the books where King gets deep into the characters. You really get to know them. You cheer for them. You sneer at some of them. You want good things to happen, it doesn't always work out.
Was the book perfect? No. I had a few quibbles. I had one aviation related problem with it. (If anyone out there is writing a book or movie and needs some information on aviation stuff, let me know. I'll be glad to help because this stuff always bugs me.) And I wasn't impressed with the very end, but it didn't ruin the book for me. Not one bit.
I think this is one of King's best books in a while. Based on the reviews I've seen, I'm not the only one. Go out and check it out. Just leave some time to read. It's long.