Why do we know where contributions come from? Why are they not anonymous? I think it'd be better if candidates had no idea where all that money came from.
The concept of a nation-state depends upon closed-source sovereignty. Anonymous money could be coming from anyone or any foreign nation-state, thus usurping and subverting the sovereignty nation state.
However, this is a problem that already exists because it is easy enough for a foreign entity to use a third party shell to do this (i.e. AIPAC).
That would make it an unaccountable black box, though. That would not be good in the interest of transparency. On the other hand, there are plenty of unaccountable black boxes already.