how were u forced to donate in residency? would you have been fired if you didnt?
It's actually a bit of a problem that you don't see the problem here, because it raises the horrid specter of the possibility that someday you might lean on subordinates to make PAC donations, and not see a problem with it then either.
When a superior nags you about donating to a cause he or she feels is worthy, there is perceived (and sometimes real) risk in not giving. Your boss should not ever be pressuring you to pay money for
anything - not PAC donations, not the local homeless shelter, not the sad-faced homeless kittens and puppies at the ASPCA, not even his daughter's Girl Scout cookies he knows you're addicted to and are going to buy somewhere anyway. Any of these are totally inappropriate.
As a side note, the military is simultaneously strict and stupid about this - any such solicitation or pressure is explicitly forbidden, which is good. But every year they do this obnoxious Combined Federal Campaign where they hand out donation signup forms where you can do recurring monthly donations to one of 100s of vetted charities in the catalog. It's sort of a nice system.
Except the $ value donated per department and per command is a source of pride ... and "accomplishments" for leaders and intermediaries to put on their fitness reports which helps them get promoted. So they wink wink push it pretty hard ... they hand out signup forms to everyone and REQUIRE that they be turned in. "If you don't want to donate, that's OK, just put your name and a zero on it so we can show we've made 100% contact with everyone." I always refuse to even touch the forms because the tactic fills me with a boiling rage, and I like being the lone holdout to thwart their "100% contact" goal.
I don't know why they think it's OK to force some (literally) poor junior enlisted kid into choosing between
A) donating $ he can't afford or doesn't want to give
B) signing his name to a form documenting what an uncaring cheapskate he is
A residency program leaning on residents to make PAC donations is the same kind of wrong. Even if there's no obvious overt consequence, it's still wrong.