While the more complex jokes often are tailored to an ethnicity or social class/group, and some of them only really work for one kind, the one-liners can usually be simply modified to whatever group you want to insult. Some adjustment is necessary anyway, if you're going to come across as telling your own jokes instead of just reciting someone else's.

For both kinds, it's generally best to reserve your needling to groups of which you, yourself, are a member or at least a close fellow-traveller - or at least get a straight man of an appropriate reputation with a good sense of humor. (And you can create any reputation you need for a regular straight man, if you can get one to stick with you for a few performances.)

"The library at the (Ag college/Presidential archive/any small town) burned down last night.
They lost dozens of really good books.
Some of them hadn't even been colored in."

John