This is only partially true.
The acts of the GOP are not inspired by any lunatic ideas of divinities and other fairy tales, like the differences between religious fanatics.
Instead, they are very cunning, practical individuals. They are not working to destroy America but to make America work for them. They have been defeated in 2008 in a very innoble way and were left red-faced. They have nothing to offer, nothing to run on but on the contrary have a big negative in Bush's disastrous presidency, so they put their bet on making Obama's presidency look as bad as possible by actively destroying as much of America as they can (here you are right in the 'destroying') so that they can blame Obama for that.
They cannot possibly believe this lie that cutting taxes benefits the economy, for example. They preach this to deceive the dumbest Americans, while the smarter ones can see through the deception but still think that the Republicans can bring some benefit to them.
And the Republicans surely can benefit some in the middle class and up: it benefits those low-lives who rather lose some while others lose much, much more, so that they, even with less wealth, get into a percent-wise higher class of wealth. In this past recession and the current bad economy, practically ALL people including the rich lost. But a person who lost A LITTLE can feel great satisfaction that he didn't loose like the ones who lost A LOT, and so his ego gets a nice boost, thanks to the GOP, and this will reinforce his feelings of being smart because he votes for the GOP.