One remarkable aspect of the US is the number of Christian denominations. One source puts it at 635, larger than any other country (Britain is second with 235). I think this is a reflection of the pioneer/self-reliant creed of the US. If you don't like some aspect of your current congregation, start your own.

The claim about religiosity of people in the US has some problems. Self reporting by people puts church attendance at 40% per week, but actual attendance surveys put the number at about half this figure. In France the number is about 15%, so 20% in the US is not that different (the UK is about 7%).

The second claim is also not borne out by statistics. Christian affiliation has dropped from 86% in 1990 to 76% a decade later. Those professing no religion have grown from 8 to 14% during the same period. There is also a drop in religiosity in the younger generation, from 37% for all adults to 27% in the 18-34 age group.

I think this is relevant because it shows that the affiliation between the religious right and the political right is based upon an effort by a minority of a minority to cement its power before demographic shifts render it powerless. This means that efforts to restore secularism in government must not be based solely on religious arguments.

There needs to be an effort which explains to those in the smaller of the 635 denominations, and to those in other religions as well, that allowing a single vision of religion to become official doctrine is dangerous to their future freedom to worship as they wish. There also needs to be an appeal to the increasing number of people who have a loose or no religious affiliation. They have to be awakened to the losses of individual freedoms that have occurred in the past, and present, when religious leaders start making and enforcing the laws.

I don't know how to bridge the gap between the "progressive" religious and non-religious sectors, but having each pursue similar goals separately only makes the effort less effective. As Oliver Cromwell illustrated, it is possible for a small group to seize control of government if the majority are in disarray. The results weren't pleasant.