My guess as to what the sticking point would be that prevents politicians from accepting Bitcoin donations - they're not known to not take anything worth money - is somehow doing so without allowing foreign donations to their campaigns, which I believe is illegal.
Currently there is little identity authentication on campaign websites. They ask for your name and address before you pay with something like paypal, but there is no means of verification.
Actually, they have to report these donations to the Federal Elections Commission (fec.gov) on a quarterly basis, even if there have been no donations for that quarter. Further there is a pretty sizable body of law around the funding received for the obvious reason that it's a tempting target for corruption.
When I was considering my run for Congress, one piece of advice I got for "free" from a guy who I had talked to about running campaigns, was to be sure I had a good idea about who everyone was that was giving me money. That had to be reported and if it turned out a law was violated it was on the candidate, not the donor in terms of consequences.
According to this guy, there were candidates who got "derailed" by opponents who arranged a big donation to be made, hoping that it would be accepted and not tracked down. Then leaking the existence of that donation to the FEC who would put the hapless candidate under investigation (and out of the race) until the investigation was resolved. This adviser suggested that politicians were despised for the same reason that used car salespeople get despised, and that was because too many of them had no morals preventing them from making progress at your expense.
Anyway, I think it is useful for the Bitcoin community to educate various politicians about what Bitcoin is, but I expect the best they can hope to do is keep them from acting directly against its interests. Getting actual support would be quite hard for a currency whose primary driver seems to be crime syndicates.
Yes, they report the information you give them on the form on their website. The form of payment shouldn't matter. You can authentic identity on a bitcoin transaction as on any other transaction if you choose to. Generate a unique address for each transaction and the bookkeeping is easy.
