Political speech to cost more at the USPS

In an obvious attempt to quash political speech within the US mails, the USPS has proposed to dramatically increase the cost of mail that does not explicitly attempt to sell something or explicitly solicit donations for a non-profit purpose. Sounding the alarm is the American Association of Political Consultants. The proposed USPS regulation can be found here.

Given that email and blogging have become so pervasive this may not matter as much as it might on first appearance. But on the other hand it seems extremely odd to raise the rates to send a "vote for me" letter and not raise the rates for a "send me money" letter.