i think those places are really interested in people who are passionate about doing that SPECIFIC work...so assure them that essentially, you are not just looking for a job...you really really really aspire to be a public defender, etc... and tell them WHY ....and maybe add in a little personal story (short) as to what drove you in that direction. Though grades are important, a lot of government jobs are more interested in passion and loyalty...unless you want to clerk for a judge...then you better be a GREAT writer.