Obama focuses on Biden's roots

Barack Obama is doing his best to capitalize on the working-class and Pennsylvania roots of his running mate, Senator Joe Biden.

Biden hails from Scranton, Pa., -- also the childhood summer stomping grounds of Hillary Clinton, who soundly defeated Obama there in the Democratic primary. So he'll be there on Labor Day to march in the annual parade, after also taking part in the Pittsburgh Labor Day parade.

The Obama campaign also released a TV ad that will air in northeast Pennsylvania in which Biden highlights his local connections, and vouches for Obama as well. The ad features childhood snapshots of both candidates.

"Everything I know about working hard I learned growing up in my grandpop’s home in Green Ridge," Biden says in the spot. "You know, Scranton’s a place that never leaves you. It becomes part of your heart.

"Barack Obama learned the same lessons, while being raised by a single mom and his grandparents," Biden continues. "Responsibility. Determination. Respect. To stand up for the dignity of all our families. So it’s good to be coming home – and bringing home a friend."

Biden represents Delaware, but also gets a lot of media coverage in neighboring southeastern Pennsylvania, particularly the Democratic stronghold of Philadelphia. Pennsylvania, with its 21 electoral votes, is a huge prize in November. Republican John McCain campaigned there on Saturday with his brand-new running mate, Alaska Governor Sarah Palin.