Ben Pershing writes for The Washington Post: “With a new Congress beginning, hundreds of new lawmakers will be sworn in Wednesday. But only one will break a record that’s lasted four decades. At the moment Sen. Barbara A. Mikulski (D-Md.) completes the oath to begin her fifth term in the chamber, she will become the longest-serving female senator, surpassing the 24-year tenure of Sen. Margaret Chase Smith (R-Maine).”