Colorado Democrat Michael Bennet was sworn in as a Senator on Thursday afternoon by Vice President Joseph Biden.

Bennet, a former Denver public schools superintendent tapped by Gov. Bill Ritter (D) to replace now-Interior Secretary Ken Salazar, assumed his post as Colorado’s junior Senator at approximately 4:10 p.m.

Biden, inaugurated as vice president on Tuesday, served 36 years in the Senate before resigning his seat last week. Salazar accompanied Bennet onto the Senate floor prior to his swearing-in.

Bennet will serve out the remainder of Salazar’s first Senate term — which expires in 2010 — and must stand for election if he wants to keep his job beyond then. Sen. Mark Udall (D), elected to his first term in November, is now Colorado’s senior Member of the Senate.