Republicans control Congress and the presidency for the first time since the 2005-07 Congress under George W. Bush. With full party control, the GOP leadership hopes to push through an aggressive policy agenda that includes repealing and replacing the Affordable Care Act, cutting taxes and easing regulations on businesses.
It won't all be smooth sailing, however. Republicans hold only 52 seats in the Senate, which is short of the 60 needed to pass most legislation.
Control of Congress
Barack Obama began his first term with full Democratic control. The 2009-11 Congress passed some of his signature policy achievements including the Affordable Care Act, an aggressive economic stimulus package and the Dodd-Frank financial reforms.
Mr. Obama was also able to protect two liberal seats on the Supreme Court with the appointments of Sonia Sotomayor and Elena Kagan in 2009 and 2010, respectively.
The Republicans went 40 years between 1955 and 1995 without ever controlling the House of Representatives but have made inroads in the last two decades.
Two-party representation at the start of each CongressDemocrats
Republicans
Tie
PresidentParty
Senate
House
Obama's first term
Democratic majorities in the 111th Congress, 2009-11
With strong majorities in both the Senate and House, Congress passed the Affordable Care Act, an aggressive economic stimulus package and the Dodd-Frank financial reforms.
Narrow majorities under George W. Bush
Republican majorities in the 108th and 109th Congresses, 2003-07
With narrow Senate majorities, Congress debated and approved the invasion of Iraq, passed tax cuts and approved aid in the aftermath of Hurricane Katrina.
Clinton's first term
Democratic majorities in the 103rd Congress, 1993-95
With strong majorities in the House and Senate, Congress passed the Family and Medical Leave Act and transformed trade relationships through Nafta and other reforms on tarrifs and trade.
The Carter years
Democratic majorities in the 95th and 96th Congresses, 1977-81
Congress under Jimmy Carter created the cabinet-level departments of Energy and Education.
The Kennedy and Johnson years
Democratic majorities in the 87th to 90th Congresses, 1961-69
A coalition of Northern and Southern Democrats held the House of Representatives for 40 years beginning in 1955 and held both chambers of Congress for most of the 1960s. Many of the social programs laid out in Lyndon Johnson’s ‘Great Society,’ were passed in the 89th Congress, including Medicare and Medicaid, sweeping civil rights protections, education reforms and environmental protections.
Voting Ideology
Both parties have taken a partisan turn in the last 20 years, especially in the House. According to DW-Nominate "Common Space" scores, a statistical comparison of the voting records of lawmakers over the course of their careers, the makeup of both chambers has drifted farther to both the left and right.
Ideological makeup of Congress
Each line represents a lawmaker over their career
Democrats
Republicans
Tie
PresidentParty
Senate
House
Source: Voteview.com
Congress and the President
One measure of bipartisan cooperation in Congress is how often lawmakers' votes align with the position of the president. The 2015-17 Congress is missing from the most recently available data, but both parties' lawmakers have tended to stick to their party's position in recent years. House Democrats gave George W. Bush little support during his administration, and House Republicans have returned the favor under Mr. Obama.
Voting with the president's positionOpposition party
President's party
PresidentParty
Senate
House
Source: Brookings Institution
A political party is made up of individuals who organize to win elections, operate government, and influence public policy. The Democratic and Republican parties are currently the primary parties in Congress.