Of the fifteen "swing states" from 2012, seven August polls have been released: Michigan, Nevada, New Hampshire, Pennsylvania, Georgia, Florida & North Carolina. So far, all of those states are going in the same direction they did in 2012, with North Carolina being the only state so far going for Trump. However, what should be very disturbing for the Trump campaign, and all Republicans hoping to win down-ballot races, is that the Pennsylvania & New Hampshire polls are blow-outs for Clinton. In 2012, Obama won Pennsylvania by 5.4%--polling now has Clinton with an 11% lead, well above the margin of error. Even more devastating, in New Hampshire, where Obama won in 2012 by 5.6%, Clinton is leading by a whopping 17%. We'll see if these leads hold as we approach the elections. But both of these polls are of "likely voters," one of the best polling predictors to measure.
The North Carolina lead for Trump gives him a 4% advantage. This is within the margin of error, and North Carolina was also the closest state for Romney in 2012--he won by just 2%. What should be more disturbing for the Trump campaign are the Georgia & Florida polls. The former has him tied with Clinton*, and the latter have Clinton up by 6%. Romney won Georgia with an almost 8% margin, and lost Florida by less than 1%. These numbers can change quite a bit by November, but if Trump has a reasonable chance to win the key swing states, he needs to have far better numbers than a post-convention, August 'tie in Georgia' & significantly down in Florida. Michigan, which Trump strategists claim is in play because of Trump's appeal to working class voters, is currently polling for Clinton at 9%, the same margin by which Obama beat Romney.
If there is a narrower set of "swingier swing states," it is likely to be eight: North Carolina, Florida, Virginia, Pennsylvania, New Hampshire, Iowa & Colorado, based on states from 2012 where the margins were won with less than 6%. Politico includes Michigan & Wisconsin on this list, although Obama won both with 7% or greater margins in 2012. While many of these states do not have August polling, those that do, combined with July polling, put all of these states in the same partisan hands as 2012. This, when one considers the absurdly substantial leads that Clinton has in the PA & NH polling, does not bode well for Trump. *Edit, Friday, Aug 5. Three Georgia polls have come out this week. One has Trump tied with Clinton, a second has Trump up by 4%, and a third has Clinton up by 4%. All three polls are within the margin of error, so all three represent a statistical tie.