I think the issue is not religiosity per se, but a certain cognitive handicap that makes it difficult for some people to deal with ambiguity, uncertainty, and complexity. This handicap is like other affective disorders (e.g. depression) - when it sets in, it makes people see everything through the prism of danger and fear (just like depression makes one everything seem gloomy). I also think that this handicap has both neurological and environmental causes i.e. some people have brains that are predisposed to it more than those of others (just like some people are more predisposed toward depression) but also that fear is caused by environmental factors that range from the lack of exposure, to social alienation, and to deliberate fear mongering.
I think what makes the US population particularly prone to this cognitive disorder is its social structure that is segregated into small and relatively isolated social groups (from small rural to gated communities). This compartmentalization result sin the lack of exposure to variety and diversity. Then there is alienation and deliberate fear mongering - nit that much by government, but by different interest groups (both left and right, political and commercial) that use fear as the means of prodding people to action.
The end result is xenophobia and the constant state of fear that triggers cognitive handicap to deal with diversity and uncertainty. To deal with that handicap, people use various mental crutches, from religion, to ideology, to arming themselves, to escaping into seclusion, and to lashing out at the perceived "threat" (i.e. anything that is "different").
I thing that behavior is universal, but it is particularly pronounced in the US (as compared to Western Europe) because of the peculiarities of the US social structure. Therefore, secularism is not the answer to this problem - you take away their religion, they will come with another mental crutch, like drugs, pop-culture, ideology etc.
Unfortunately, I do not see any solution to this problem anywhere in sight. The US society is heading towards even greater segregation and compartmentalization, and even more intensive fear mongering campaign - so we will most likely see more of this fear of uncertainty.
I am afraid that a ticket to Canada or Europe may be the only quick way out. A longer term solution must almost certainly involve going with the flow of that compartmentalization toward greater state sovereignty and eventual breakup of the federal entity.
This may sound very farfetched tight now, but when in 1979 I read a political pamphlet by a Russian dissident wondering if the USSR would survive to the year 2000 I wished I had some of that stuff he'd been inhaling. Indeed no sane person would dare to make that prediction in 1979, but ten years later USSR was history. Now, if you think of the effects of oil price increases, denominating international trade in euro instead of the dollar, or the increased international cooperation to counterweight the US influence will have on the US economy, and if you add the culture war that is only going to intensify - the downfall or at least serious reconstitution of the federal entity aka the US start looking like a possibility.
Wojtek