The money quote 1:
The important political fault lines in the American religious landscape do not run along denominational lines, but cut across them. That is, they are defined by religious outlook rather than denominational labels.
For instance, traditionalist Catholics are closer to traditionalist Evangelicals than to modernist Catholics in their views on issues such as abortion or embryonic stem cell research.
The survey also found that traditionalists in all three major faith groups overwhelmingly identify with the Republican Party — and that traditionalist Evangelicals do so by a 70% to 20% margin. The margins among Mainline Protestant and Catholic traditionalists are less lopsided but nonetheless solidly Republican. On the other side of the divide, modernists in all these religious traditions as well as secularists strongly favor the Democrats. Modernist Mainline Protestants, for example, now favor the Democrats by a more than two-to-one margin.
Money quote 2:
Via email from The Eclectic Econoclast pointing to this post by Hispanicpundit.
Historically, religious fissures in the political arena have tended to break along
denominational lines rather than by level of religious commitment.
Throughout much of the 19th and 20th centuries, tensions between Protestants and Catholics often took on a partisan cast. During the 1930s, for example, New Deal Democrats overwhelmingly won the support of Catholics, as well as white and black Protestants in the South. Republicans, on the other hand, drew the bulk of their support from white Protestants inthe Northeast, Midwest and West.
These patterns held until the 1960s, when a major realignment began to take place, prompted by a mix of racial and social issues that would come to define the "culture wars" of the ensuing decades.
Unfortunate for politics and religion that on average the less dogmatic are also the less religiously committed.