No, seriously, save the Arecibo Observatory!
tl;dr: the Arecibo observatory is a unique, extremely useful Nobel-winning piece of science equipment, it is far from having done all it’s capable of, it runs on a comparatively shoestring budget and of course it’s the one thing they want to shut down for “savings”.
If you only have a few seconds, you can go to the poll here (and no, apparently you don’t need to be from the US to take it).
If you have a few minutes, you can also write them a letter here.
(Note: this post may bend the rules a bit, I’m not sure - please tell me if it is so)
edit: typo