I'm a pretty firm believer that just about every single aspect of an individual, from their personality/tendencies to appearance and everything in between, is gene-regulated. That being said, I don't think I ever considered the possibility that you're born with a predisposition to be either Conservative or Liberal.
DRD4, the gene that codes for dopamine receptor 4 in humans, has recently been linked to a tendency for individuals to be politically liberal. A medical genetics professor at UC San Diego, in reference to the new finding, asserts that "we hypothesize that individuals with a genetic predisposition toward seeking out new experiences will tend to be more liberal - but only if they had a number of friends growing up." Being more open to new experiences is only one aspect of having a "more liberal personality", if it is at all.
Whether you consider yourself to be a Republican, a Democrat, Libertarian, or even a member of the Rent is Too Damn High Party (see video below), you're only one to a certain degree. Political ideology is on a spectrum, due to the amalgam of platforms and issues. Can we really associate an individual's propensity to try new things with being politically liberal? Are there any personality traits we can really link to voting one way or the other? I personally think political views are one of those things that are mostly influenced by environmental factors (SES, upbringing, friends, etc.) rather than genotype, which could explain why/how an individual's political views can shift with age/environment.