From the New York Times:
The McCain campaign’s recent angry tone and sharply personal attacks on Senator Barack Obama appear to have backfired and tarnished Senator John McCain more than their intended target, the latest New York Times/CBS News poll has found.
After several weeks in which the McCain campaign unleashed a series of strong political attacks on Mr. Obama, trying to tie him to a former 1960s radical, among other things, the poll found that more voters see Mr. McCain as waging a negative campaign than Mr. Obama. Six in 10 voters surveyed said that Mr. McCain had spent more time attacking Mr. Obama than explaining what he would do as president; by about the same number, voters said Mr. Obama was spending more of his time explaining than attacking.
Over all, the poll found that if the election were held today, 53 percent of those determined to be probable voters said that they would vote for Mr. Obama and 39 percent said they would vote for Mr. McCain.