Reply #8: You forgot the spokesperson part. Check out this article — it pretty much

[NYCGirl]

spells it all out.

http://slate.msn.com/id/2110985/

Excerpt:
Part of the mystery comes from the fact that the job description is changing. The DNC chairman will still be responsible for coordinating the party's daily message, for building the organization that handles the mechanics of electing presidential candidates, and for raising the money that funds that organization. But in the 1990s, one of the chief jobs of the party chairman was to "relate to a group of wealthy donors who financed literally a majority of the party's activities," former DNC national chairman Joe Andrew said. Now that six- and seven-figure party donations are prohibited, the importance of big donors has decreased. In 1996 and 2000, the DNC conducted the functional equivalent of the national TV campaign for the Democratic presidential nominee. The McCain-Feingold reforms put a stop to that, too.

Joe Andrew argues that the days of "chair as business leader, chair as fund-raiser" are coming to an end, and that future chairs will be more likely to play the role of political strategist. He may be right. But up to now, as Andrew put it, "There is no time, at least in the television era, where the national chair has really defined who the party is and what the party is all about."