Newark Mayor and U.S. Senate candidate Cory Booker speaks to the media after casting his ballot during the Senate primary election in Newark, New Jersey, August 13, 2013. Booker seemed poised for victory on Tuesday as New Jersey voters head to the polls to select party nominees in the race to fill the state's empty U.S. Senate seat. (REUTERS/Eduardo Munoz) Sen.  Cory Booker (D-N.J.) (Eduardo Munoz/Reuters)

Cory Booker was sworn in as the newest U.S. senator Thursday, becoming the first black man elected to the Senate since Barack Obama in 2004 — and the sixth man to represent New Jersey in the Senate this century.

Booker, 44, was sworn in at noon by Vice President Biden. With his arrival, the Senate Democratic caucus now includes 55 senators — 53 Democrats and two independents — and Republicans have 45 seats.

Before the ceremony, Senate Majority Leader Harry M. Reid (D-Nev.) called Booker "a great asset to the nation."

Dozens of Booker's family, friends and supporters watched from the Senate Gallery, including CBS newscaster Gayle King and Bonnie Englebardt, the wife of the late Sen. Frank R. Lautenberg (D-N.J.). Dozens of Senate Democrats and a handful of House Democrats, including Reps. John Lewis (D-Ga.) and James Clyburn (D-S.C.) were on the Senate floor to witness the swearing in. Only three Republican senators attended, including Sen. Tim Scott (R-S.C.), the chamber's only other black senator.

Booker won a special election last week to succeed Lautenberg, who died in June at age 89. Republican New Jersey Gov. Chris Christie appointed Jeff Chiesa to hold the seat until last week's special election.

Lautenberg's first term ended in 2001, and he was succeeded by Sen. Jon Corzine (D-N.J.), who served for five years until he was elected governor and was succeeded by Sen. Robert Menendez (D-N.J.). Lautenberg ran again for the state's other seat when Sen. Robert Toricelli (D-N.J.) opted not to run for reelection in 2002 amid an ethics investigation. Chiesa replaced Lautenberg in June, and now Booker is taking the seat.

Despite the tumult, two other states, Massachusetts and Minnesota, have been represented by more senators this century. Like New Jersey, Missouri also has been represented by six senators this century.

Three other black men have been appointed to the Senate since Obama's 2004 election: Sen. Roland Burris (D-Ill.), who filled out the remainder of Obama's term; Scott, who was appointed to the seat of former senator Jim DeMint (R-S.C.) in January; and Sen. Mo Cowan (D-Mass.), who served six months this year in the seat formerly held by John F. Kerry (D-Mass.), now secretary of state, before Sen. Edward J. Markey (D-Mass.) won the seat in a June special election.

Booker and Scott plan to run again next year for full six-year terms.

Here's the video of Booker's swearing-in:

Vice President Joe Biden presided over the swearing in of former Newark Mayor Cory Booker on the Senate floor Thursday. (The Washington Post)

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