Best field trip ever. When Ben Affleck visited Washington, D.C., March 26 to testify before the Senate Appropriations Committee, wife Jennifer Garner and their eldest daughter, Violet, 9, elected to join him. “It was Violet’s idea,” a source says of the third grader, who watched as the Eastern Congo Initiative founder spoke about the importance of continuing foreign aid in Africa, detailing how the organization’s efforts will significantly improve the lives of 100,000 locals. “Jen is very supportive of everything Ben does, and so are their children.” (Younger tots Seraphina, 6, and Samuel, 3, stayed in L.A.) Mom also got a shout-out during the two-hour hearing, when Affleck raved about her “extraordinary work” with early childhood education in America. “She’s extremely effective,” the Oscar winner, 42, said. “And we’re all…
