There are lots of things that predict your politics to varying degrees: age, gender, sexual orientation, whether you have children, education, income, job, where you live, to name a few. These can be used together to fairly accurately predict at least whether you lean left or lean right.<p>In any given election in the US you have about 40% of the general population who votes Democrat always, 40% who vote Republican always and 20% who decide the election results. Even the massive landslides of Reagan in 84 and Nixon in 72 didn't go more than about 60-40.<p>Politics on a mass scale is so predictable that maps are produced of political leanings that are used for redistricting.<p>A lot of these same factors can be used to predict music tastes. Age and where you grew up are probably the two biggest. So don't make the mistake that many in the press often do and mistake this for causation for correlation. Correlation isn't surprising given the common factors.