Why do Progressives treat their voting blocks like dumb sheep & tell not to check out opposing views like Beck?

How can people grow by only listening to one side of an argument? If someone isn't telling the truth are they to be feared or exposed by watching their information & checking it for yourself? The progressives only support viewing sites that seem to be lying & omitting information about like Baghdad Bob did in Iraq. We know why Saddam didn't want his people exposed to other sources. Are Progs operating in the same way?