There are many, obvious reasons why it's got to be easier to be a prosecutor than a public defender. There's the fact that people assume that the prosecutor is always right. There's the fact that you get to decide your own caseload (to a certain extent). There's the fact that if you decide on the day of trial you have a crappy case, you can just dismiss it (I'd love to be able to do that!).
However, there are a number of less obvious reasons why it's easier to be a prosecutor. It's the less obvious reasons that make me resentful of prosecutors. I expect that people will believe the prosecutor because they are the prosecutor. The obvious reasons--I anticipate those things. The less obvious reasons, the secret ones that you don't realize until you have to deal with them are the ones that make me wish that every prosecutor would be required to do a couple years as a public defender.
