They get selected by advancing through the chairs ~ do this party job, get elected to that position, do something else, bring in campaign money ~ and eventually it's YOUR TURN.
Intelligence and patriotic fervor are NOT requirements to be a Chicago representative. Never have been. Never will be.
In the 60s one of the Chicago Representatives was wholly owned by the Syndicate. It put him in and he became head of the House Finance committee. Another had Sam Giancana’s son-in-law as his chief of staff.
Kinda thinking that’s not too far from the Pubbie way either....