But notice how many of the women who trail her are currently serving. Only the light-colored bars are those who will be retired at the end of this term. The closest (who isn't retiring in 2016) is Marcy Kaptur, who, at 68 years old, could certainly serve the additional eight years it would take to depose Mikulski. (Mikulski will be 79 next year.)
Mikulski's 38 years on Capitol Hill is remarkable -- though somewhat shorter than the all-time tenure record, held by John Dingell, who served over 59 years. In fact, Mikulski is only ninth on the list of longest-serving members among those who are currently in Congress, a function of the far higher number of men in Congress, particularly 40 years ago.