Tapping a network of Democrats sensing an upset in Delaware County's congressional race, challenger Joe Sestak was able to raise more money in the last three months than his opponent, U.S. Rep. Curt Weldon. The retired Navy admiral, a political novice, took in $700,000 in the quarter that ended June 30, his campaign staff said yesterday. By contrast, Weldon raised $400,000, said the Republican's campaign manager, Michael V. Puppio Jr. Sestak has now raised a total of $1.1 million since he entered the race. "For a first-time candidate, it is very unusual to raise that kind of money, particularly against...