The practice of congressional earmarking has a long history. But in recent years, its use has skyrocketed, and earmarking has emerged at the center of high-profile scandals, including the one that sent former Rep. Randy "Duke" Cunningham of Rancho Santa Fe and former lobbyist Jack Abramoff, both Republicans, to prison. Those scandals involved earmarks that led to the personal enrichment of lawmakers. There is no evidence of that in [Hillary] Clinton's case. (by Tom Hamburger and Dan Morain. Los Angeles Times. December 10, 2007.)
She is personally enriched by this. She takes campaign funds from developers and military contractors, etc. In turn, she earmarks funds for their projects. With the campaign funds, she pays for all the costs of campaigning that others cannot afford. She gets elected. She pulls down a large salary and many benefits and perquisites. When she retires, she'll be given huge sums for books and speeches and consulting, etc., just as her husband. Together, they will have amassed a sizable fortune all from ostensibly serving the public when in fact it is the corporations they serve first and foremost.