U.S. Democratic presidential nominee Barack Obama is leading his Republican opponent John McCain by 53 percent to 34 percent among early voters, a new poll indicated Tuesday.

　　The poll was conducted by the Pew Research Center among some of the 12 million voters who have already cast ballots six days ahead of the presidential election day on Nov. 4.

　　At present, 34 U.S. states allow voters to cast a ballot before election day, either in person at the polling site or by mail.

　　The long October queues at polling places anticipate a tremendous surge in voter turnout over previous elections, and statistics from key states indicate an advantage for Obama.

　　Campaigns, voters and election workers have increasingly embraced early voting this year.