At the risk of sounding both academic and liberal, let's consider some data. Analysis of the Bush-Gore National Election Survey once again shows the strong correlation between education and ideology. Of the population with less than a high school diploma, there are none who identify themselves as liberal (much less extremely liberal). On the other hand, 26 percent of high school dropouts see themselves as conservative.
If your interest is to avoid liberals or simply maintain conservative beliefs, your safest bet is to drop out of high school. That's because completing the 12th year of schooling has a demonstrably liberalizing effect on the population. Through, perhaps, self selection or as a result of exposure to new ideas, 20 percent of those who finish the 12th grade see themselves as either slightly or moderately liberal (though well less than 1 percent identify as "extremely liberal"). But conservatism still reigns at this level; 37 percent of those with only 12 years of schooling are among the ranks of the conservative.
Thus, apparently, high school teachers merit a measure of suspicion as well, for college simply furthers high school's effect on the attitudinal distribution. It is only among the college educated, however, that we identify a significant liberal population. Of those with a college diploma, 25 percent self-locate left of center. While 7 percent of high school grads see themselves as extremely conservative, only 3 percent of college grads do.
Interestingly, the percentage of liberals falls slightly at the post-graduate level. This is largely explained, however, by the incomes associated with the variation in post-graduate education. If you account for income -- for example, the difference between Ph.D.s who teach and MBAs or M.D.s who earn comparatively enormous sums in the private sector -- the strong positive relationship between education and liberalism reappears.
The problem lies, therefore, not with university hiring practices and certainly not with the evil machinations of liberals bent on ruining our youth. In fact, there is no problem here. The absence of larger numbers of conservative faculty members is, to a great extent, explained by the very correlation between education and ideology. Other explanations might relate to the different choices that liberals and conservatives, especially those with advanced degrees, make about education, careers and income.