Upper strata more consistently support rightist parties than lower strata support leftist ones.

Evidence

Perhaps the simplest and most obvious consequences are those that depend on the fact that reduced constraint with reduced information means in turn that ideologically constrained belief systems are necessarily more common in upper than in lower social strata. This fact in turn means that upper social strata across history have much more predictably supported conservative or rightist parties and movements than lower strata have supported leftist parties and movements. — John T. Jost and Jim Sidanius, Political Psychology, 1963