Editor and Publisher notes polls in previous years have shown "that roughly 5 to 10% of voters (or more) felt that editorials had some influence when they cast their ballots. In a battleground state that's not insignificant."
That said, here's the scorecard: "Sen. John Kerry now holds a fairly narrow lead in the number of endorsements, but he has gained many more of the larger papers, holding about a 17 million to 12 million edge by circulation. Most telling, however, is that at least 35 papers that backed Bush in 2000 have now switched to Kerry, and another nine that supported Bush before have declared their neutrality this year. Only five so far have gone from Gore to Bush."
A complete list of newspaper endorsements is also provided.