oh what a lot to catch up with. I am with bk and jimjams - I wouldn't find selective criteria a problem as long as parents have a real choice of schools - and if you want to add political selection to that, you can.
Talking personally, I wouldn't consider sending my sons to any school with a rigid selection criteria based on parents beliefs and commitment - athiest, christian, tory, labour. But as long as a good choice of schools exist, I don't object to more rigid schools existing.
I do not want to push my beliefs down my sons throats and would not want them to have a narrow view of the world. However, if any school said we broadly follow beliefs a, b, and c, which as you know are beliefs of 'x' relgion or political group, if those broad beliefs fitted my broad beliefs I'd have no problems choosing the school. I have a mental list of things that are important to me about a school, and just seek a school that matches them. Simple as that really.
I freely admit my sons' education is at the mercy of my and dh's beliefs. That's a given fact. If we believe it's important to have a good holiday each year and a new car, then we won't be able to afford to educate them privately, no matter how much they winge on about it and work their socks off. If we believe football is a boring waste of a Saturday afternoon, then they won't be having football coaching. If we believe they must excel at a musical instrument, then they will be made to learn the piano. It's not fair, but children do not rule the world.