Rep. Duncan Hunter (R-CA)—on the ballot for reelection in his San Diego district—used campaign donations to pay for golf balls, groceries, private-school tuition for his children and an airfare for the family’s pet rabbit, according to the corruption charges federal prosecutors brought against him last month. Perhaps he stands alone in allegedly breaking the letter of the law, but he is far from the only lawmaker using money from donors to subsidize a personal lifestyle and access luxury travel and golf resorts.