[hota_mazi]

I understand there is some truth to that claim, but how real is it?

Sentences are delivered by judges. There have been prominent examples of judges bribed by prison systems to deliver harsh sentences, but that doesn't seem to be the norm.

Am I naive thinking that most judges deliver the sentence they believe is just, and that if something needs to be reformed, it's their perception of justice and not just the prison system?

[t-writescode]

Mandatory minimums are what primarily dictate a lot of sentences anymore; and, those can be very arbitrary, especially with 3-strike laws.

Often, legislature decides the sentence length due to mandatory minimums.

[chrisco255]

Sentences are basically tightly constrained within some guidelines. The judge has leeway for leniency, but not much. Otherwise there's a preset range for each crime (i.e. 6-12 months) based on offender's history (i.e. first offender's get less time, etc) and population risk, judge can lower that by up to some maximum amount.

So then it really needs legislative reform to adjust those minimum sentences.

[zinckiwi]

In the US judges tend to be elected. That's not the norm around the world. US judges must to a certain extent be politicans, and "being tough on crime" plays well to the electorate. Many probably do feel their sentences are appropriate, but if they are collectively anchored towards harsh sentences the end result is the same.