The chairman of the Senate antitrust committee is in the headlines this morning after he urged regulators to block AT&T’s proposed acquisition of T-Mobile USA. Democratic Senator Herb Kohl of Wisconsin wrote a letter to the heads of both the Department of Justice and the FCC, saying the proposed tie-up would harm consumers and violate antitrust laws. That’s bad news for AT&T, of course, but it’s worth noting (as the Washington Post does) that Kohl also opposed Comcast’s joint venture with NBC Universal. So while many of us believe that Kohl’s assessment is absolutely accurate, it may not mean much in the long run.