The charts above represent the feelings of Iowa GOP caucus voters. The top chart is the current picture, and the bottom one is what those voters thought last October (just four months ago). One thing that is very apparent is the volatility of the Republican race for president -- at least at this very early stage. The two charts show some rather stark differences.
Another thing that is clear is that Jeb Bush is not a favorite of Iowa Republicans. Although he gained 4 points since October (going from 4% to 8%), there are four other Republicans that Iowa voters prefer over him (Carson, Huckabee, Paul, and Walker) -- and a fifth place finish in Iowa would certainly not be a great way to start a presidential campaign.
But perhaps the most significant thing about these polls is the rather remarkable movement of Wisconsin Governor Scott Walker. He has moved from only 4% support in October to 15% currently -- and is now the leader among all the candidates in Iowa. That 15% is not a prohibitive lead by any means, but it does show he may be a more significant player in the 2016 campaign than many have given him credit for.
That poll also looked at the preferences of Democratic caucus voters (and those results are shown in the chart below). There really hasn't been much movement among Democrats. Clinton had a prohibitive lead in October, and she is still maintaining that huge lead -- while Warren finishes a distant second and Biden third.
These charts all represent numbers found in a new Des Moines Register Poll -- done between January 26th and 29th. The survey questioned 402 registered Republicans saying they will attend their caucus, and 401 registered Democrats saying they will attend their caucus. The margin of error for both parties is 4.9 points.