I been stopped by cops a shiload of times, LAPD, Burbank PD, and Glendale PD. Somewhat annoying, but they have always been very respectful towards me. Once you start getting really defensive with Cops... you make them nervous, and scared. Especially if you are under the influence of something. Just stay calm.
That whole American citizen excuse is just asking for ass kicking. It's really patronizing, and many cops are former combat vets who find that especially insulting from someone who literally didn't get shot at for their country. Not trying to defend Cops. Just saying stay calm, and avoid getting into a fight you probably won't win.