[L]et’s look at where Obama’s job approval fell significantly from 2012 to 2013 and where it remained relatively steady — or remained identical (in one state) or improved (in three). Nationally, Obama’s Gallup job approval in 2013 (46.5 percent) was down 4.5 percentage points from his 2012 popular vote percentage of 51.
Let’s start off with the 2012 target states, including the quasi-target states of Michigan, New Mexico and Pennsylvania. I have rounded off the changes to integers, since tenths of a percentage tend to be distracting and are without statistical significance.
New Hampshire: -8
New Mexico: -8
North Carolina: -8
The reader will note that Obama approval has dropped farther (percentage point-wise) than the national average in every one of these states except Florida. That seems plausible: The Obama campaign spent great effort boosting his job approval there in 2012 and that effort has not been sustained in the non-election year of 2013. This is good news for the Republicans, and especially because there are Democratic Senate seats up in six of these state (Colorado, Iowa, Michigan, New Hampshire, North Carolina and Virginia) which Republicans seem to have some chance of winning. There are also nationally significant and probably seriously contested governor races in Colorado, Florida, Michigan, New Mexico, Ohio, Pennsylvania and Wisconsin. …
… Obama’s numbers don’t seem to have changed much in the South, except in West Virginia (-10), where resentment over his “war on coal” is raging, and in the two target states of Virginia and North Carolina. This is predictable if we suppose that black voters’ approval of Obama remains high, while white voters’ approval was always low.