This isn't surprising. White people are more likely to identify as liberal/socialist.
Most Blacks and Hispanics aren't actually left-wing. They are centrists. The only reason they vote Democrat is because that party keeps them 'on the plantation' by scaremongering that the GOP is 'racist.' If minorities switched to the GOP, the Democrat party would be taken over by far left socialists who could never win, which is why the Democrats wave the bloody shirt of 'racism' all the time. The notion that Republicans are racist is not true, as any minority Republican will tell you.
Poll
