Poll: McCain, Obama in virtual dead heat

WASHINGTON, Aug. 14 (UPI) -- The major party U.S. presidential candidates are in a virtual tie just weeks before the parties' nominating conventions begin, a Pew research poll indicates.

Forty-six percent of registered voters asked said they favor or lean toward presumptive Democratic nominee Sen. Barack Obama, D-Ill., while 43 percent back Sen. John McCain, R-Ariz., his likely Republican rival, the Pew Research for the People and the Press results released Wednesday indicate.

In late June, Obama held a 48 percent-to-40 percent margin over McCain.

Pew said two factors may be the reason for the shift. First, McCain is getting more support from the Republican base than in June; and second, the Arizona Republican has made gains in his leadership image.

Obama has made little progress in increasing his support among core Democrats since June, researchers said.

Among swing voters, Pew results indicate 12 percent lean toward Obama, 11 percent favor McCain and 10 percent are undecided.

Survey results are based on telephone interviews conducted July 31-Aug.10 of 2,414 registered voters. The margin of error is plus or minus 2.5 percent.