What fact would support the claim that Juvenile courts are not as democratic as other courts?

The fact that there is no trial by jury.

Explanation:

A court would be considered as 'Democratic' if the citizens have a certain amount of influence in determining how a certain case should be rules.

In Juvenile courts, the case that came only revolved around small-scale misbehavior.  To make the process become faster all of the decisions were made by judges without any intervention from juries.

This is why compared to other courts, juvenile court is considered to be less democratic.