“has the country become so secular that any sign of religiosity will scare off a majority of voters”?
An excellent point. Is Florida too secular for a guy like Santorum these days? I think it might be.
Does a country ever swing “back” from secularism?
Yes
Communism collapsed in the former USSR and Evangelical Christians have been growing in numbers in Russia. China is still communist but the govt has not been able to stop the growth of Christianity there. It seems that that there is a long process where a country embraces an all powerful State and becomes secular in the process. Then the society begins to collapse and near the bottom the people turn back to God.
We are seeing Europe heading down this road. Increasingly the populous expects govt to provide everything and the nations are becoming more secular. Also their economies are collapsing and their birth rates are so low that their population is declining. We are on the same road, just not as far down it as they are.