Who went and made Lauer campaign ethics czar?

Matt Lauer is not the only self-professed journalist to try to impose on others what he thinks are his better ethics. What I want to know is, who asked him?
Lauer, a host of NBC's "Today," was the moderator earlier this week of a debate or forum (or whatever) between the (two major) California gubernatorial candidates. The site was a California "women's conference" (read "liberal women's conference," and reactions from the audience bear me out; it was a lot like watching "The View"). The campaign between Jerry Brown and Meg Whitman has become increasingly hard fought, even bitter. Brown has called Whitman a "whore" (in the political sense, but a whore all the same). I'm sure Whitman has gotten her licks in.
In his usual namby-pamby, Rodney King way, moderator Lauer besought the two candidates, "Could we get the two of you to promise not to run anymore negative [he did not define "negative," natch] campaign commercials?" Brown, the Democrat man, said something like, "Well, I'd sure be willing to try," and got big cheers from the audience. Whitman, the Republican woman (and probably the only Republican woman) at the women's conference, said she would be glad to, but not at the expense of the truth or the issues. Big grumbles, boos and hisses all around.
The responses were totally predictable. But the main question remains, "Who is Matt Lauer to issue such a 'challenge' in the first place?" Put another way, "Why does it seem to be the supposed guardians of free speech who often seem to want to limit it?" because Lauer is hardly the first to decry "negative campaigning."