Hillary Clinton crisscrossed Pennsylvania and unveiled a last-minute television ad invoking Pearl Harbor and Osama bin Laden, in hopes that a big victory in the state's Democratic primary Tuesday could turn around her long-shot presidential bid.

While she is widely expected to win Pennsylvania, a new financial report showed the New York senator's campaign struggling for cash. That could limit her ability to stay competitive in the final nine Democratic contests with Barack Obama, who has considerably more money to spend on...