WASHINGTON (AP) — Declaring an end to “a sad chapter in Illinois history” Republican Mark Kirk was sworn in Monday as the U.S. Senate’s newest member, giving him seniority over fellow newcomers set to join the chamber in January.

Kirk pledged a bipartisan, centrist approach but also quickly took aim at Democrats he said had squandered the public’s goodwill.

“Our state’s leaders tried to sell this seat, then blocked an election to fill it,” Kirk said at a reception following his swearing in. “But the courts, the law and the people spoke.”

Kirk is replacing Sen. Roland Burris, who was appointed by scandal-tarred former Illinois Gov. Rod Blagojevich to fill the remainder of President Barack Obama’s Senate term. Illinois voters in November elected Kirk to fill out the remainder of Burris’ term and for a full, six-year term after a tight race with Democrat Alexi Giannoulias.

The ascent of Kirk, a five-term congressman, from the House to the Senate means Republicans will now have 42 votes in the Senate — a number that will rise to 47 in January. Being sworn in now gives Kirk a small, but important, seniority advantage over other incoming senators, who won’t be sworn in until next year.

Kirk was led into the Senate chamber by the last Republican to represent Illinois in the Senate, former Sen. Peter Fitzgerald, and his new colleague, Sen. Richard Durbin, the Senate’s No. 2 Democrat. He was then sworn in on the floor of the Senate by Vice President Joe Biden.

After Kirk took his pledge to serve, the chamber burst into long, sustained applause. Kirk was then greeted by dozens of senators from both parties and members of the Illinois delegation. The new senator smiled broadly throughout the handshakes and embraced Sen. John McCain, R-Ariz., who he has cited as a mentor.

Kirk then moved down the hall of the Capitol to the ceremonial old Senate chamber, where he posed for pictures before hustling on to a packed reception in a Senate office building. Kirk then outlined his approach to governing to the crowd, which included fellow members of Congress, some prominent lobbyists and supporters who had flown in for the event.

“I will serve as a fiscal conservative, a social moderate and national security hawk,” Kirk said. “I will reach out to all 99 other senators to help balance the budget, defend America and grow our economy.”

As if to prove the point, Kirk then broke with his party for his first vote. He voted with a majority of Democrats and a handful of Republicans to move forward a food safety bill supported by Durbin.

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