The United States' ultimate political power couple, Bill and Hillary Clinton, celebrate 40 years of marriage today. It's been a rocky union at times, especially during the 1990s when the former president faced allegations of infidelity and then an actual affair with White House intern Monica Lewinsky. But the pair remained together and rededicated themselves to the Clinton Global Foundation, Hillary Clinton's political career, and, recently, a grandchild. Here's a look at some of the ups and downs of their marriage: 1970: Bill Clinton and Hillary Rodham meet at Yale Law, where they are