Snapedom

And if he did lose his magic, it's difficult for me to picture him being happy about it. I can see him wanting to leave the wizarding world behind post-war, but not voluntarily giving up his magic. It clearly gave him pleasure as a child and made him feel special, and it was something that he had in common with his beloved Lily.

On the other hand, magic might have unpleasant associations now, due to his time with the Death Eaters. He might feel guilty that he cast spells and created potions that were used to hurt people, even indirectly. I still think that he wouldn't want to give up his magic completely, but a good fanfic author can convince me that he might want to give it up as penance for his crimes, or simply leave all painful memories of his past behind.

However, even if he wanted to give up his magic, I still think he would be reluctant to give it up, simply because it would make him incredibly vulnerable and put him at the mercy of any wizard or witch who wanted to take revenge on him. Even if his name was cleared after the war, I'm sure that there would still be many people who would hold grudges: the relatives of Death Eaters who were killed or imprisoned, or people victimized by the Death Eaters who don't believe in Snape's innocence, or fellow Order members who can't forgive him for killing Dumbledore, even though they now know that it was at Dumbledore's own request. He'd be in great danger if he didn't have magic to defend himself.

His best defense would be to disappear completely into the Muggle world, taking on a new identity, and maybe faking his own death. Although, again, a good fanfic writer could probably convince me that Snape could set up some Muggle type of defense--I assume that even a wizard can be killed by a bullet, although it's difficult for me to picture a gun-toting Snape. ^_^

Of course, it's entirely possible that Snape's magic might be stripped away from him against his will, whether by accident--an unexpected effect of the backlash of a Dark spell, for example--or by design, such as the Ministry stripping his powers from him. (Although that latter scenario would definitely have to be fanon, since we don't see any evidence in canon that this is possible, otherwise the Death Eaters in Azkaban would probably have been stripped of their magic, rather than having to rely on Dementors to guard them.)

A Snupin story called "Methods of Suicide" by jedirita fits the first scenario nicely. I also mentioned this fic in my Snape and the Muggle world essay, and here's how I described it:

He's not exactly a squib, but due to curses he suffered during the war, attempting to use magic causes him excruciating pain. So he is trying to adapt to living in the Muggle world again, and finding it difficult. Even though he is half-Muggle, he has spent so much time in the wizarding world that the Muggle world has become unfamiliar to him.

The loss of his magic, a sense of isolation (somewhat self-imposed), guilt over his murder of Dumbledore, and the fact that he's alone at Christmastime when everyone else is with their friends and family, all combines to send Snape into a deep depression, and he contemplates suicide, but can't make up his mind which method to use. Meanwhile, Lupin shows up unexpectedly, and seems stubbornly determined to befriend Snape in spite of his protests that he neither wants nor needs Lupin's friendship. It's more pre-slash than slash, and Snape's problems don't magically disappear, but Lupin is able to offer him a gesture of hope that gives him the strength to go on. It's a very beautiful and moving story.

pir8fancier's Snape, the Home Fries Nazi (a famous Snarry fic) shows a more positive "Squib Snape" portrayal. When Harry killed Voldemort, all the Death Eaters, including Snape, lost their magic--it had something to do with the way the Dark Mark connected them to him. And since Harry was also connected to Voldemort, due to his scar, he is also losing his magic, and has been driven suicidal by that loss. Snape has vanished from the wizarding world, and is now working as a fry cook in Arizona, where Harry tracks him down and wants to know how Snape has managed to live with the loss of his magic and whether there's any way to get it back. The answer to the second question is "no," but Snape tells Harry that even without his magic, he is able to take satisfaction in finally being free and having to answer to no one but himself. It was that argument that convinced me that Snape could be happy as a Squib--after being beholden to two masters for so long, I can definitely see him cherishing his freedom, even without magic. It's an extremely well-written story, and was able to convince me to go against my usual inclinations: I don't normally care for the Snarry ship, and as I mentioned, I have a hard time envisioning a happy Squib Snape. But the author took that ridiculous premise--Snape as a bald fry cook in Arizona--and totally made me believe it. The relationship with Harry was very convincingly portrayed, too, as their relationship starts off as adversarial and slowly develops into friendship and finally, love.

So maybe I can picture a Squib Snape, after all!