I wish I had an answer. I don't think Americans are overly conservative. They just prefer to think of them selves as conservative because conservative = good & xtian and liberal = bad or utopian right now.
People want all kinds of progressive things like universal health care or guaranteed cost of living raises but the US is full of people who are very afraid. Conservatives use this fear to manipulate people into voting against their own self interests. At least I believe this to be true. Maybe I'm dilusional. The US is a less homogenous country than most and that plays into the hands of those who pander to fear.
John Thornton