Yes, McGrath, but the party still tends to select a leader who they think will appeal to a broad cross section of the public. (given that though, it's still sometimes rather surprising what unappealing individuals they can come up with)

A Jewish or a JW candidate would be seen as a bit of a risk, and those guys really hate taking risks they don't have to. Similarly, a female candidate for the top job is a bit of a risk. It's been tried once, unsuccessfully.

It can always happen, though, that someone with extraordinary drive and tenacity breaks through such a barrier. Example: Margaret Thatcher in the UK. I detested her, but she was a tough one, no doubt about it.