There are currently 45 senators (this includes Senator Kerry’s successor) that have served less than six years and 39 of these senators are still serving in their first term. In eleven states – CO, CT, HI, IN, MA, ND, NE, NH, NM, VA and WI – both senators have served less than six years.
Since the 2012 elections, changes in the Hawaii and Massachusetts delegations have drastically altered seniority in both states and the Senate. When Senator Inouye passed away, the Senate lost its most senior member and Hawaii lost its seniority as a state in the Chamber. Both Sens. Schatz and Hirono have served less than 2 months, a major change from the long careers of Sens. Inouye and Akaka. Schatz is considered Hawaii’s senior member, since he was sworn in on December 27, 2012 and Hirono was sworn in on January 3, 1013.
Now that Kerry has submitted his resignation to become Secretary of State, Massachusetts lost the seniority it held for decades. Kerry was the seventh most senior senator and Ted Kennedy, before he passed away, was the second most senior member. Once Kerry’s seat is filled, both Senators from Massachusetts will have been in office for less than a year (This will still hold true if Scott Brown is elected to take Kerry’s seat. He lost his seniority when he left office in January 2013 after losing to Elizabeth Warren).
Two states that still hold considerable seniority in the Senate are Iowa and California. For Iowa, Senator Grassley is the sixth most senior senator, followed by Senator Harkin who is seventh. Iowa’s position will change following the 2014 election now that Harkin has announced his retirement. California holds the fourteenth and fifteenth most senior spots, with Sens. Feinstein and Boxer. Senator Leahy from Vermont is the Senate’s most senior member, and President pro tempore.