I'd say for some people who take the test, they come out more left than they do, but when they scale the politicians, they come out more right than they should.
Political practice is frequently more authoritarian than the median opinion on the street, it's the nature of the beast - when you're inside and have the tools available, you see a broader and more interventionist role in culture and social policy.
And governmental economic policy is generally a lot more neoliberal than the median opinion on the street.
So the gulf between elected officials and real people's results is perfectly natural.