I did, and to answer that question – and countless more about other hashtags – I just published on hashtagify.me the first beta version of a new “top influencers” feature.
With this feature, when you visually explore Twitter hashtags, following their relationships, you can also see up to 6 of the top influencers for the selected hashtag. These users are listed by name, ranked by their estimated influence, and shown on a graph where you can also see their relative influence (y-position), how specialized they are on that hashtag (x-position), and how many followers they have (bubble size).
This feature is still in beta and the hashtags usage data is still being collected: This means that, especially for the less used hashtags, the influence estimate isn’t very precise. Still, while I’m working on augmenting the data collection rate for this kind of data, you can already get an idea about the influencers on your topics of interest. And a similar feature is in the works about the top websites for an hashtag: Stay tuned!
Oh, and by the way: It looks like the top influencer about #debt is @MikeBloomberg, the Republican mayor of New York, followed by @WestWingReport, an independent White House journalist – you can see it for yourself here. Where are the Dems??