Rasmussen has released the results of polling Obama vs a list of Republicans for the 2012 election. What do those numbers say? Well, nothing terribly conclusive, but it depends on how you look at them.
First of all, the raw numbers, given with the R number first and Obama second:
Romney: 40-45, Palin: 38-48, Huckabee: 43-43, Gingrich: 37-49, Paul: 34-42, Pawlenty: 35-45, Daniels: 32-45, Cain: 25-43, Barbour: 34-42, Huntsman: 31-42.
Sorting these by the difference gives:
Huckabee 0, Romney -5, Paul & Barbour -8, Palin & Pawlenty -10, Huntsman -11, Gingrich -12, Daniels -13, Cain -18.
What if we look at just the R numbers and sort them?
Huckabee 43, Romney 40, Palin 38, Gingrich 37, Pawlenty 35, Paul and Barbour 34, Daniels 32, Huntsman 31, Cain 25.
These numbers really shouldn't surprise anyone; they're roughly sorted by national prominence. What about if we sort by Obama's numbers?
Gingrich 49, Palin 48, Romney & Pawlenty & Daniels 45, Huckabee & Cain 43, Paul & Barbour & Huntsman 42.
Doesn't look good for Gingrich and Palin there, but consider that Paul ties for best in this. This ranking also suffers because these candidates were almost all polled against Obama at different times during the month of March. What if we take Obama's approval numbers during the time of each polling (his approval varied from 49 to 42), and subtract Obama's approval from Obama's number against each candidate at the time? Then we get this:
Gingrich +3.5, Palin +2, Huckabee 0, Pawlenty & Daniels & Huntsman -1.5, Romney & Barbour -3, Cain -3.5, Paul -4.
This still doesn't look good for Gingrich or Palin, but suddenly Huckabee doesn't look nearly as good as he had been. Romney improves a bit, Cain looks good, but again Paul comes out the best in this comparison, so again we can't read too much into this.
All of these numbers should of course be taken with a pinch of salt at this point in the campaign (especially since they seem to favor Ron Paul); Rasmussen's margin of error is +/- 3 points, so about all we can really conclude is that Newt Gingrich matches up worse against Obama than Herman Cain or Ron Paul.