By Amanda Becker and David Lawder
WASHINGTON (Reuters) - U.S. Senate Democrats expanded the ranks of their party leadership on Thursday to include Senator Elizabeth Warren, a leader of the party's liberal wing and a possible presidential contender in 2016.
Democrats, who lost control of the Senate in last week's elections, created a new post for Warren as a strategic policy adviser to help the party bolster its appeal to the middle class.
Democrats also voted to keep Harry Reid as their leader but not before venting frustration at his tactics and Senate gridlock during a nearly four-hour meeting.
"Harry Reid is a good man. I just felt we needed a leadership change," said Senator Joe Manchin, who was one of at least two Democrats who opposed Reid.
Warren, a rising party star from Massachusetts, spearheaded the creation of the Consumer Financial Protection Bureau after the 2008 financial crisis and is a frequent critic of big banks.
"I think Senator Elizabeth Warren, as much if not more than any other senator, drives Wall Street crazy," said Senator Richard Durbin, who will remain the Democratic whip. "She is smart, she is effective, she knows how to deliver a message that really resonates with working families."
Senate Republicans unanimously confirmed Mitch McConnell of Kentucky as their next majority leader and re-elected the rest of their current leadership slate.
In the House of Representatives, Republicans voted to keep their leaders with almost no dissent, nominating John Boehner as speaker and electing Kevin McCarthy as majority leader and Steve Scalise as majority whip. Luke Messer, who just won a second term in Indiana, was chosen as the party's policy chairman, filling a vacant position.
The show of solidarity for Boehner after sweeping Republican election victories marks a shift from early 2013, when more than a dozen House Republicans voted against him amid dissent over the "fiscal cliff" tax increases, which he put to a vote over the objections of party conservatives.
The speaker is formally elected by the entire House. That vote will take place when the new Congress convenes in January with a stronger Republican majority.
Thursday's vote also confirmed support for McCarthy and Scalise, who were elected in contested votes in June following the primary defeat of then-Majority Leader Eric Cantor.
House Democrats will choose their leaders next week.
(Reporting by Amanda Becker, Susan Cornwell and David Lawder; Editing by John Whitesides, Lisa Von Ahn and Steve Orlofsky)