WASHINGTON (CNN) - Arlen Specter was in the driver's seat when the Senate Judiciary Committee grilled the two newest Supreme Court justices back in 2005, but the Pennsylvania senator won't be front and center next time.
Specter jumped from the Republican party to the Democratic party last week, putting the Democrats within reach of a 60-seat "supermajority" that could make it all but impossible for Republicans to block Democratic legislation.
On Tuesday the Senate confirmed that the party switch dropped him to the bottom of the heap in terms of seniority.
That means he will be the very last to speak when the Judiciary Committee questions President Barack Obama's yet-to-be-named nominee to replace Justice
David Souter - after even Sen. Ted Kaufman of Delaware, who has been a senator for all of four months.
In fact, only two of the 18 other senators on the committee have been in the upper house longer than Specter - and he has been in the Senate longer than seven other committee members put together.
But there is more at stake than Specter's ego or bragging rights.
The old saw "rank hath its privileges" holds true in the U.S. Senate as in few other places. With seniority comes the ability to influence legislation.
Specter lost his seniority on other committees as well, including the powerful Appropriations Committee - the one that doles out money. He's now junior to Montana's Sen. Jon Tester, who has been in the Senate since 2007.
Specter has been citing his seniority on the Appropriations Committee as he hits the campaign trail as a Democrat.
"My senior position on appropriations has enabled me to bring a lot of jobs and a lot of federal funding to this state," Specter said at a town hall meeting on Monday.
Over and over, he made a point of telling an auditorium filled with medical faculty and staff about the hundreds of millions of dollars he delivered to the Keystone State, thanks to the power he's accumulated in his 29 years in the Senate.
"Pennsylvania has a big interest in my seniority, a big interest," he said.
A day later, the Senate has stripped him of that seniority. The resolution, which set out committee assignments for the entire Senate, was approved on a unanimous voice vote.
–CNN's Dana Bash and Kamalpreet Badasha contributed to this report.