Also, I'd question the "hundreds of thousands marching under the Mexican flag".   What's the source--and date--of that one? Articles I read indicate that protesters in general are aware of the propaganda windfall that sort of behavior hands the other side--and therefore march under US flags, a fact which for some reason is not mentioned by the right-wing press.

Re :Jan: One specific incident:   she wanted to protest in front of the White House--I think it was against Ringling Bros for mistreatment of elephants--as part of a Humane
Society group.   She asked the Humane Society point blank:   if I as a member of this protest were arrested, could I be deported?   Answer: Yes; please don't come to the protest.

I actually think that any non-citizen participating in a street protest is foolish: even if not deported, you are playing into the hands of your opposition.