Are the justices on the US Supreme Court Democrat or Republican?

US Supreme Court justices do not advertise their party affiliation because they're not supposed to consider partisan ideology when making decisions. Unfortunately, in the real world, ideology plays a major role in constitutional interpretation and decision-making.

The current Court leans toward conservatism: five justices were appointed by Republican Presidents and often support the Republican agenda; four were appointed by Democratic Presidents and typically support a more liberal agenda. Sonia Sotomayor, one of President Barack Obama's Supreme Court appointees, has stated she's registered as an Independent.