LAS VEGAS - Forget the jokes about caucusing in brothels, or trawling for votes amid the slots and blackjack tables along the neon-drenched Strip.When Democratic presidential hopefuls come calling on Nevada, the real challenge will be the party faithful they find in this independent-minded state, which will host the West's first nominating contest in a little over a year.Democrats here like guns, loathe taxes and see nature as a source of fun and profit, not a place to be locked away by some Washington bureaucrat. And skip the Rust Belt rhetoric about all those manufacturing jobs fleeing to China and …