The proposed disclosure rules appear to target anonymous political speech -- that is, they intend to force any group raising and spending money on campaigns or issues to disclose who their contributors are and how much they've given. The rationale behind people wanting to be anonymous, to avoid disclosure, is not to circumvent the limits on political contributions, but rather to avoid negative publicity, reprisals, retaliation and the like. Some people will be at risk of losing business, of losing their jobs, or receiving other harassment if their political inclinations become known. There is already a chilling effect on free speech and political participation, and that's without this new rule.
Notably, the Attorney General concedes that this fear of political reprisal is legitimate. The explanation for the rules includes a provision that organizations whose donors fear reprisal if they are disclosed publicly can napply for a waiver. But this option admits that such reprisals and "blowback" can and does occur. Now, since its occurrence is admitted, doesn't it then make sense to acknowledge that there is a value to one's privacy and anonymity? Isn't there a right to anonymous speech?
And, to be real, isn't that chilling effect the very point behind this rule? Isn't this all about discouraging unpopular political speech, to kneecap your political opponents by cutting off their funding source by threatening their supporters with being revealed?