I understand your overall point but the truth is McCain was the guy that was always the liberal media's favorite bacause was a "maverick" that would cross party lines. The youngest voters will not know him that way but anyone over thirty will - whether they support him or not.
The polls are too erratic, have different questions, sample sizes, party affiliation percentages, type of voter etc. to be too disparate to possibly show an honest average.
If McCain drives home some of the unknowns, radical associations etc. of Obama he is not so much trying to change the minds of those made up but to motivate some that may have been sitting out because of indifference, anger at the Republicans in general or simply waking up from a lifelong MSM fantasy production of objective reality.
This is not over because more people than one may think are going to vote a split ticket that goes for McCain at the top and Dems all the way below; their own comfortable version of balance of powers.
Yeah, I was saying long ago "McCain, you are seriously deluded if you think the news media who love you so much are going to support you now." I recall Chris Matthews oozing love for McCain long ago--the last bit I saw on Youtube, you'd think McCain had just bashed Matthews' puppy with a shovel.
McCain was just shockingly unequipped to deal with Obama at these debates. McCain's "suspending his campaign" can now be seen as a complete mistake, and since then he's been failing, and looks it. Obama is calm--like the mannequin he is. That's what these "nonideological" swing voters want.
You're right, of course, we may see people split the vote if McCain and some 527 ads can get people wondering about Obama. But this is cutting it very close.