As U.S. Rep. Steve Kagen (D, WI) tries to make clear on the campaign trial, he's a family man. So much so that his campaign is increasingly becoming a family enterprise. Even on the money side. Kagen's four children recently gave the maximum donation of $4,600 to Dad's campaign fund for a total of $18,400, records show.The kids - who range in age from 18 to 26 and are listed as students - all turned over their donations on Sept. 30, the last date of the reporting period. Three of the siblings maxed out on the same day in 2005,...