Republicans take control of Congress today for the first time since 2006. The new legislative session starts with the controversial Keystone oil pipeline likely to be the first battleground issue and a precursor of fiery confrontations to come with US president Barack Obama.
Eyes will be fixed on new senate majority leader Mitch McConnell, the Republican from Kentucky, and House of Representatives speaker John Boehner to see if they can quell rebellious conservatives within their party and govern with the support of enough moderate Democratic senators to put Bills on the president's desk.
The Grand Old Party (GOP) won control of the senate and extended its majority in the House of Representatives in November's mid-term elections, putting Republicans in a position of strength for Mr Obama's final two years in the White House and the run-up to the 2016 presidential ballot.
Partisan gridlock may remain in this legislative session but the roles in the congressional stalemate may reverse with Republicans becoming the protagonists and the Democratic president the obstructionist.
Senate majority
The Republican majority in the senate, at 54 to 46, still means that Mr McConnell needs at least six middle-ground Democrats to overcome a filibuster to send Bills to the White House. Republicans are unlikely to be able to secure 67 votes in the senate, the number required to overcome a presidential veto.
For the 1,700-mile Keystone pipeline that will carry tar sands oil from Canada to refineries on the Gulf of Mexico, Republicans are likely to have enough votes to reach the magic number of 60 given the support of some Democrats when it narrowly fell in a vote last month.
Mr McConnell has said the Keystone pipeline will be the first Bill of the 114th Congress, but it may also be the first veto of 2015 given the president’s opposition.
The Republican senate leader is planning measures to roll back Mr Obama’s environmental regulations and his healthcare law, a key achievement of the president’s first term so despised by Republicans.
“[People] are tired of inaction – they want us to act,” the Republican senator told CNN on Sunday.
Veto pen
This puts Republicans on a collision course with Mr Obama, who warned in an interview broadcast last week that he will use his “veto pen” to block GOP challenges on the environment and healthcare.
His immigration orders, protecting millions of "undocumented" migrants from deportation, and the restoration of diplomatic and trade ties with communist Cuba will be among the other issues mobilising intense opposition from Republicans in the coming months.
The GOP has threatened to use the “power of the purse” to contest Mr Obama’s plans by seeking to take away funding, though the party has stepped back from another government shutdown given the damage inflicted on it from the 16-day federal closure in 2013.
The sheen from November’s big electoral wins for Republicans has lost some lustre.
The majority party enters the 114th Congress on the defensive after reports appeared over the Christmas break that house majority whip Steve Scalise, the third highest-ranking Republican in the lower chamber, had spoken to a white supremacist group in 2002.
Republican Congressman Michael Grimm of New York was forced to resign after pleading guilty to tax evasion. Mr Boehner backed Mr Scalise but helped to jettison Mr Grimm.
