The KidsVoting Stoughton program, part of the nationwide KidsVoting USA, held a mock election Tuesday, with 1,391 Stoughton residents under age 18 participating in eight town precincts. Just as many town residents did, they split their ticket. They voted overwhelmingly for President Obama over Mitt Romney, 850 to 454, but gave Scott Brown 818 votes to Elizabeth Warren’s 539 votes in the US Senate race. The KidsVoting Steering Committee that runs the event, co-chaired by Sharon Fradkin and Lynn Jardin, principal of the Gibbons School, is nonpartisan and completely volunteer-run, said Fradkin. The program started in Stoughton in 1998 and has been held every two years since for gubernatorial and presidential elections. Pat Basler, another member of the committee, said the program could not be held without the cooperation of Town Clerk Cheryl Mooney and her staff.