This week Gallup polled four Republican candidates against Barack Obama. For the three leading Republicans the results are typical, and do more to show the difference between polls of adults and polls of registered voters (Gallup polled both).

But oddly enough, Ron Paul was different.

The facts: 1026 adults, 879 registered voters. MoE is given as 4 for both. A quota of mobile phone responders was required, so they were covered in addition to land lines.

Among registered voters, most of the races are close. Romney leads 48-46, Perry ties at 47, Paul trails 45-47, and Bachmann trails 44-48. The chances of each candidate leading Barack Obama are 59 Romney, 50 Perry, 40 Paul, and Bachmann brings up the rear with a 30%.

That wasn’t why this poll caught my attention though. No, what’s interesting is the shifts when going from Registered Voters to Adults. Romney +2 goes to -1, Perry even goes to -4, Bachmann -4 goes to -5, but what about Ron Paul? He gains. He goes from -2 to -1. Paul’s 40% chance of a lead becomes 45%, near coin flip territory, when the sample includes people who are not registered to vote.

Of course it’s meaningless electorally, but it’s interesting to note, I believe. Republicans tend to do worse among Adults, but Ron Paul is the exception to that rule it seems. His support is unlike other Republicans, in that he does better with people who don’t vote.