which aspect of US politics is most closely tied to the concept of indirect democracy (need for apex)

Some cities allow citizens to hold town hall meetings to vote on new laws.

Explanation:

In indirect democracy, the citizens can influence the laws that the government pass by electing representatives that advocated for the law rather than voting for the law themselves.

This can be seen on the interaction in hall meetings.

In hall meetings, government representatives will directly talk to the citizens and hear their concern. During that talk, the citizens could give the representatives with their aspiration to the representatives.