Okay, more on Mehlman.
It seems what Ken Mehlman is likely referring to is the existence of 'firewalls' within the RNC in which one group or shop within the committee is running the ads and he's not supposed to involve himself in those decisions. Here's a page
about how these firewalls work.
But I doubt very much that Mehlman is prohibited from saying, when asked, whether a public ad should be pulled down.
If you're an election law expert, drop us a line and tell us what you know.