There were somehotly contested congressional primaries Tuesday as new challengers squared off against incumbents in a year when all 12 of New Jersey’s seats in the U.S. House of Representatives are up for grabs and the state’s Democratic primary ballot underwent a big change. But in the end, the sitting lawmakers and party leader-backed candidates won. That included the tough race for a freshman congressman whose father, U.S. Sen. Robert Menendez, is facing federal corruption charges, a challenge to New Jersey’s oldest lawmaker and a seat that’s open because Rep. Andy Kim is running for Menend…