09/06/2007 09:58 pm ET Updated May 25, 2011

More on the Clemson University SC Poll

One quick follow-up on that Clemson University Palmetto
survey (release,
of South Carolina
voters we linked
to earlier. We neglected to include a "hat tip" to the Politico's always
attentive Ben Smith who posted the survey last night, but also pointed
that the release showed "Obama's favorables dropping."

The release does show Obama's favorable rating among
Democrats** dropping from 82% to 63%, but the base used to calculate those numbers
was not spelled out clearly and may have been a little confusing.

The Palmetto Poll release
reported favorable and unfavorable ratings for each candidate that were calculated
as a percentage of those who had "heard of" that candidate. The poll shows the "heard
of" percentage for Obama increasing from 58% in October 2006 to 91% in the new
survey last month, while showing his "Favorable" percentage dropping from 82%
to 63%. So if I recalculate Obama's favorable rating the way most pollsters do
-- as a percentage of all respondents -- it actually increased from 48% to 57%.

Obama's ratings a year ago among were quite unique: He was not
as well known as Clinton (nationally) and Edwards (in South Carolina), but
those who knew Obama were unusually enthusiastic. Now, all three candidates are
nearly even in South Carolina in terms of how their recognition translates into favorable rating (though
Obama's rating is now slightly lower than Edwards or Clinton as a percentage of
whose who know him).

**It may have been a bit unclear in the Palmetto Poll
release, but their sample of 400 Democrats heard only questions about the Democratic
candidates, while their separate sample of 400 Republicans heard only questions
about Republican candidates. Thanks to David Woodward at the University of South
Carolina who helped clear this up.