Why Is VP-Elect Joe Biden Still A Senator? : It's All Politics Joe Biden will resign his Senate seat on Thursday — making him the 14th in Senate seniority in history.

Why Is VP-Elect Joe Biden Still A Senator?

I'll admit it had me puzzled.

Barack Obama resigned his Senate seat, to no great fanfare, back on Nov. 16. And while no one foresaw the circus that would result in Illinois from his resignation, it certainly seemed to make sense at the time. With the Senate coming back for a lame-duck session, Obama felt that his priority should be his transition from senator to president.

But what about Joe Biden? Previous senators who became VPs were already gone from the Senate by now. Al Gore, Dan Quayle and Lyndon Johnson all gave up their Senate seats in early January, just before the new Congresses were sworn in. Walter Mondale and Hubert Humphrey gave up theirs in late December. But not Biden. The vice president-elect has held onto his Senate seat; in fact, he was sworn in for a seventh term last week.

That subject came up during last Wednesday's Political Junkie segment on NPR's Talk of the Nation, and I didn't have an answer for it.

Carrie David of Newark, Del., does.

Carrie directed me to this posting on Delawareonline.com from Nicole Guadiano of the Wilmington News Journal:

A smiling Joe Biden took his seventh oath of office among friends on the U.S.Senate floor Tuesday, hitting a personal and historic milestone before becoming the next vice president.

At age 66, he was the youngest person ever sworn in for a seventh full Senate term, a fitting distinction for someone first elected at the age of 29 in 1972. He is the longest-serving senator in Delaware history and among the longest-serving senators in U.S. history.

"In all my life, the greatest honor bestowed upon me has been serving the people of Delaware as their United States senator," he said in a statement. "It is truly humbling today to take the Senate's oath of office for a seventh time." ...

Biden chose to extend his Senate service even after President-elect Barack Obama resigned from his Senate seat shortly after the election. His friends said taking his final Senate oath was important to him.

"He wants to be able to tell his grandchildren he did it," said Mark Gitenstein, a Biden adviser who previously served on his Senate staff. "I just know that he feels it's important. He's told me that. I've been in meetings where he said, 'I really want to do this one last time.' "

Kaufman said, "We all encouraged him to do it. It's historical."

It was a part of history that we weren't aware of. Biden will resign from the Senate this Thursday at 5 p.m. Eastern time. Ted Kaufman, a former top aide, has been appointed to serve in his stead until 2010, when a special election will be held ... and, conveniently, when Biden's son Beau -- the state attorney general -- will have returned from his National Guard stint in Iraq just in time to run for his dad's seat.

No. 14. By extending his Senate tenure to Jan. 15, Biden snuck past Claiborne Pell (D-RI) and Pete Domenici (R-NM) and will be the 14th-longest-serving senator in history.

1. Robert Byrd (D-WV) -- 50 years

2. Strom Thurmond (D/R-SC) -- 47 years, 5 months

3. Ted Kennedy (D-MA) -- 46 years, 2 months

4. Daniel Inouye (D-HI) -- 46 years

5. Carl Hayden (D-AZ) -- 41 years, 10 months

6. John Stennis (D-MS) -- 41 years, 2 months

7. Ted Stevens (R-AK) -- 40 years

8. Ernest Hollings (D-SC) -- 38 years, 2 months

9. Richard Russell (D-GA) -- 38 years

10. Russell Long (D-LA) -- 38 years

11. Francis Warren (R-WY) -- 37 years

12. James Eastland (D-MS) -- 36 years, 3 months

13. Warren Magnuson (D-WA) -- 36 years, 2 weeks

14. Joseph Biden (D-DE) -- 36 years, 11 days