American voters get their overall impression of the candidates from traditional media. This includes the networks, news magazines, and newspapers. Although the internet is more influential this year than in the past, the majority of mostly uninvolved voters are still influenced by how the traditional media covers the competing tickets. Cable news and talk radio have some influence as well but are primarily preaching to the choir: higher information voters who are pretty well set in their preferences one way or the other.
The swing portion of the voting public is not all that obsessed with every twist and turn but will eventually vote their feelings and comfort level on election day. This is where the dominant themes presented selectively by the traditional media influence the elections.
There can be no doubt that we were very badly served in 2000 and 2004 by continuous and dominant media themes that demeaned and disrespected our candidates while promoting Bush/Cheney as "great guys" in 2000 and "stronger in a dangerous world" in 2004. The "anti-Dem" coverage by the traditional media was about 80-20 against in my estimation. And yet Gore won the popular vote and Kerry came within an ace of taking Ohio and the EV.
Why? As Dems we do have a substantial advantage in party identification margin... this year it is up to about 15% according to the most thorough study by Pew in March
http://pewresearch.org/pubs/773/fewer-voters-identify-as-republicansThe Pew study split the electorate as follows by identification: 36% Dem, 27% GOP, 37% IND. (as a side note Dems have likely improved a bit since March according to registration drive figures). The Dems lose a bit in this since a larger number of nominal Dems (10-12%) vote GOP than vice versa (8-10%) historically. But this is more than offset by the IND vote which splits their 37% as follows: Dem-leaning 15, GOP-leaning 10, Non-leaning 12.
The popular vote margin in this election will likely be decided by that low information group of non-leaning INDs, about 12% of the electorate. This is the group most influenced by "comfort level and feelings" rather than policy analysis or traditional affiliations.
How the traditional media presents the candidates to this group over the next two months is a key. The tendency of media themes is toward the negative so the question is whether that consistent negative slant against the Dems continues from 2000 and 2004 (as we have seen through the past month or so until recently) or now evens the playing field with the weird and controversial news coming out of the McCain/Palin ticket remains to be seen.
So far I like our chances.