Since the 1970s, self-described "conservatives" have outnumbered "liberals" by a substantial margin, often almost 2:1. That raises a number of questions, notably how the Democrats, as the more liberal party, manage to remain competitive. One possibility is that many people don't think of liberal and conservative in a political sense--when they say they're conservative, they're referring to lifestyle or religion rather than politics. Few surveys have asked questions that get at this issue, but back in 1981 the Gallup poll asked "People who are conservative in their religious views are referred to as being right of center and people who are liberal in their religious views are referred to as being left of center. Which one of these categories best describes your own religious position?" and followed with the same question about political views. The survey also had a number of questions on seven political issues: abortion, the death penalty, government spending on social programs. I divided people into two groups based on education (high school or less vs. some college or college graduate) and looked at how well you could predict what they said about their political views from political opinions and what they said about their religious views. I summarize this by giving the unique contribution to explained variance.
No college College
Political Opinions 4.1% 10.8%
Religion 10.7% 9.9%
Total 17.5% 37.7%
The total is bigger than the sum of the two contributions because there's some overlap between religious rating and opinions on political issues (religious conservatives have more conservative opinions on the political issues), and if you do the calculations, you see that the overlap is much bigger for college-educated people. Putting this together, what less educated people say about their political ideology doesn't have that much to do with "politics."