Senate Democrats will have smaller majority in lame-duck sesssion

Kirk captured the Senate seat that belonged to President Obama. He won a special election to serve out the final weeks of Obama’s first term as well as an election to serve a subsequent six-year stint.

Manchin was elected to complete the term of the late-Sen. Robert Byrd (D-W.Va.), who was re-elected a record ninth time in 2006.

Coons will fulfill the remaining four years of former Sen. Joe BidenJoseph (Joe) Robinette BidenBiden: Trump family separation policy could make the US a pariah Elizabeth Warren can unify Democrats and take back the White House Giuliani doubles down on Biden comments: 'I meant that he’s dumb' MORE’s (D-Del.) seventh term. Biden left the Senate in 2009 to become Barack ObamaBarack Hussein ObamaObama to visit Kenya, South Africa for Obama Foundation in July Overnight Energy: EPA declines to write new rule for toxic spills | Senate blocks move to stop Obama water rule | EPA bought 'tactical' pants and polos Clarifying the power of federal agencies could offer Trump a lasting legacy MORE’s vice president.

Kirk will give Republicans control of 42 seats during the lame-duck session, meaning that Democrats will now have to win over at least two GOP votes to pass end-of-year agenda items.

The practical impact may be minimal because Republican senators have balked at making solo defections on tough votes. Throughout the 111th Congress, Senate Majority Leader Harry ReidHarry Mason ReidAmendments fuel resentments within Senate GOP Donald Trump is delivering on his promises and voters are noticing Danny Tarkanian wins Nevada GOP congressional primary MORE (D-Nev.) has had to persuade small groups of centrist Republicans to cross the aisle to pass jobs legislation and extensions of unemployment insurance.

Manchin may prove to be a tougher vote for Democratic leaders to corral than Sen. Carte Goodwin (D-W.Va.), whom he picked to fill in for Byrd temporarily.

Manchin ran as an outspoken opponent of President Obama’s agenda and went so far as to fire a bullet into a copy of energy reform and climate legislation in a television ad. He also vowed to cut federal spending and repeal what he called the “bad parts of Obamacare.”

Democrats have a list of legislation they want to pass in the lame duck.

They must vote on an extension of the 2001 and 2003 tax cuts passed under President George W. Bush, which expire at the end of the year. They must also consider an omnibus appropriations bill or a stop-gap funding measure to keep government funded beyond Dec. 3.

They may also look to extend unemployment benefits, which expire at the end of this month, and freeze a scheduled cut in doctors’ Medicare reimbursements.