system
Given the following post, respond as if you're commenting on Reddit:
human
How comes the Senators in the United States usually come from powerful families while in Europe Union the parliamentarian are mostly clerks and teachers and the likes?

With Europe I can understand: As a parliamentarian you can create a humble fortune and secure a decent future for your kids. The parliaments are a spring board for the little humble bourgeois who are more cultured than the rest, i.e. for bureaucrats and clerks. These people are also more exciting for the lobbying groups because they are more easily influenced. But in America the parliamentarians are drawn from the elites. 

Social science, how comes?
gpt
In one of his working papers ("Why Are There So Few Working-class People in Political Office? Evidence from State Legislatures"), Nicholas Carnes highlights the important role of labor unions in providing a space in which working class people can develop politically useful skills and in recruiting working class people to run for political office.   Applying this argument in comparative context, the weakness of American labor unions relative to their European counterparts could explain some of this difference.