It's been a few years since I was in the classroom.  However, I'm guessing the policy of requiring prior signed parental approval for any "field trips" is still in place.  

You mention three extremely "hard-right" patisan events.  Fifth graders demonstrating in support of addressing global warming is hardly comparable to your examples.  Yes, I know you're a member of the ever-diminishing population of "climate change deniers",  that's your right.  However, the facts of climate change are so widely supported and the scientific community is so united in recognition of climate change, that we're no longer talking about an "opinion."  I'm sure somewhere in the world there still exist "flat-earthers".  I'm sure some still believe the Earth is the center of the Universe.  You show us that there are still a few who still deny global change around as well.  No wonder you're so fond of Donald Trump.