Did Obama or Clinton serve in Vietnam?

During the 2004 elections, John Kerry wore his purple hearts on his sleaves! Everybody was on Bush's case for only serving in the Air National Guard, while John Kerry was a decorated Vietnam War Veteran (supposedly). So where was Hillary Clinton nd Barak Obama while John McCain was in a POW camp? If Vietnam service was so important when John Kerry was running for president, why isn't Vietnam service important now that Clinton and Obama are running?