Yafit Cohn with some meaty data:

While political contributions/lobbying proposals remain prevalent, companies should be mindful that they rarely pass, regardless of whether they are supported by the proxy advisory firms. Issuers often successfully oppose political contributions/lobbying proposals, typically highlighting in their opposition statements legally mandated disclosures already in place and the additional cost of duplicating such disclosures. In determining how to respond to a shareholder proposal on political contributions and/or lobbying, companies should assess the level of disclosure, if any, that is appropriate for the company and should feel comfortable opposing the proposal if they feel it is in the best interests of the company and its shareholders.

The complete publication, including footnotes, is available here.