J. Scott Applewhite/AP Photo

Maine's newly elected Independent senator-elect, Angus King, announced today that he'll caucus with the Democrats in the Senate, boosting the party's control to 55 seats, compared with 45 held by Republicans in the new Congress.

"I have decided to affiliate with the Democratic Caucus because doing so will allow me to take independent positions on issues as they arise and at the same time be an effective representative of the people of Maine," King announced in Congress this morning.

King underscored remaining independent even with his caucusing with the Democratic Party and will become one of two Independents in the Senate, along with Sen. Bernie Sanders, I - Vt., who also caucuses with the Democrats.

King noted that the decision was "relatively easy" after the Democrats' victories on Election Day.

"In the situation where one party has a clear majority and effectiveness is an important criteria, affiliating with the majority makes the most sense," King said. "The majority has more committee slots to fill, has more control over what bills get considered, and more control over the Senate schedule."

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But he left open the door to the possibility of caucusing with the Republicans if in a new Congress Republicans were able to take back control of the Senate.

"It would be a question of the majority but also a question of, which I emphasized, on my ability to maintain my independence."

King won his seat with 55 percent of the vote, replacing the retiring Republican Sen. Olympia Snowe.

Senate Majority Leader Harry Reid, D-Nev., welcomed King into the Democratic caucus, noting that he and the Democratic caucus embraces his Independence.