Congressional Quarterly has analyzed the roll call voting patterns of members of Congress since 1953. The three principal studies involve:
The frequency with which lawmakers vote with the president when he clearly indicates his preferences (Presidential Support).
The frequency with which they vote with their party, on occasions when a majority of Republicans oppose a majority of Democrats (Party Unity).
And the frequency with which they show up and cast "yea" or "nay" votes (Voting Participation).
This interactive graphic shows 2009 Party Unity, Presidential Support and Voting Participation scores for individual lawmakers in office at the close of the session. Scores are based on the 397 roll-call votes cast in the Senate, and 991 roll-call votes cast in the House (the House also conducted four recorded quorum calls so far this year).
Alabama Rep. Parker Griffith switched party affiliation from Democrat to Republican, effective Dec. 23, 2009. All votes cast by Griffith in 2009 were as a Democrat.
The Speaker votes only at her discretion. As is traditional, House Speaker Nancy Pelosi, D-Calif., has not participated in most roll-call votes so far this year, so her scores may not fairly represent her positions.
Rep. John Garamendi, D-Calif., was sworn in Nov. 5 to fill the seat vacated by fellow Democrat Ellen O. Tauscher, who resigned June 26 to become an undersecretary of State. The first vote for which Garamendi was eligible was 858; the last vote for which Tauscher was eligible was vote 477.
Rep. Judy Chu, D-Calif., was sworn in July 16, 2009, to fill the seat vacated by fellow Democrat Hilda L. Solis, who resigned Feb. 24 to become secretary of Labor. The first vote for which Chu was eligible was vote 549; the last vote for which Solis was eligible was 79.
Rep. Mike Quigley, D-Ill., was sworn in April 21, 2009, to fill the seat vacated by fellow Democrat Rahm Emanuel, who resigned Jan. 2 to become President Obama’s chief of staff. The first vote for which Quigley was eligible was vote 194; Emanuel was not eligible for any votes in 2009.
Rep. Scott Murphy, D-N.Y., was sworn in April 29, 2009, to fill the seat vacated by fellow Democrat Kirsten Gillibrand, who resigned Jan. 26 to become a senator. The first vote for which Murphy was eligible was vote 221; the last vote for which Gillibrand was eligible was vote 29.
Rep. Bill Owens, D-N.Y., was sworn in Nov. 6 to fill the seat vacated by Republican John M. McHugh, who resigned Sept. 21 to become secretary of the Army. The first vote for which Owens was eligible was 867; the last vote for which McHugh was eligible was 719.
8 Del. Gregorio Kilili Camacho Sablan of the Northern Mariana Islands, who was elected in 2008 as an independent, informed the Speaker on Feb. 23, 2009, that he wished to list his party affiliation as Democrat. The first vote in the Committee of the Whole for which he asked to be counted with the Democrats was vote 100.
Senate:
Sens. Joseph I. Lieberman, I-Conn., and Bernard Sanders, I-Vt., caucus with the Democrats, and their party unity scores are calculated as if they are Democrats.
Sen. Michael Bennet, D-Colo., was sworn in Jan. 22, 2009, to fill the seat vacated by fellow Democrat Ken Salazar, who resigned Jan. 20 to become secretary of Interior. The first vote for which Bennet was eligible was vote 11; the last vote for which Salazar was eligible was vote 5. Salazar was not eligible for any presidential support votes in 2009.
Sen. Ted Kaufman, D-Del., was sworn in Jan. 16, 2009, to fill the seat vacated by fellow Democrat Joseph R. Biden Jr., who resigned Jan. 15 to become vice president. The first vote for which Kaufman was eligible was vote 6; the last vote for which Biden was eligible was vote 5. Biden was not eligible for any presidential support votes in 2009.
Sen. George LeMieux, R-Fla., was sworn in Sept. 10 to fill the seat vacated by the Sept. 9 resignation of fellow Republican Mel Martinez. The first vote for which LeMieux was eligible was vote 274; the last vote for which Martinez was eligible was vote 272.
Sen. Roland W. Burris, D-Ill., was sworn in Jan. 15, 2009, to fill the seat vacated by fellow Democrat Barack Obama, who resigned Nov. 16, 2008, to become president. The first vote for which Burris was eligible was vote 5.
Sen. Paul G. Kirk Jr., D-Mass., was sworn in Sept. 25, 2009, to fill the seat vacated by fellow Democrat Edward M. Kennedy, who died Aug. 25. The first vote for which Kirk was eligible was vote 299; the last vote for which Kennedy was eligible was vote 270.
Sen. Al Franken, D-Minn., was sworn in July 7, 2009, after he was certified the winner of that state’s contested election. The first vote for which he was eligible was vote 218.
Sen. Kirsten Gillibrand, D-N.Y., was sworn in Jan. 27, 2009, to fill the seat vacated by fellow Democrat Hillary Rodham Clinton, who resigned Jan. 21 to become secretary of State. The first vote for which Gillibrand was eligible was vote 16; the last vote for which Clinton was eligible was vote 6. Clinton did not participate in any presidential support votes in 2009.
Pennsylvania Sen. Arlen Specter switched party affiliation from Republican to Democrat, effective April 30, 2009. The first vote he cast as a Democrat was vote 174. His scores for the Party Unity and Presidential Support studies reflect his votes as a Democrat. As a Republican, Specter was eligible for 135 party unity votes; his party unity support score was 56 percent; opposition score, 44 percent; participation rate, 100 percent. As a Democrat, he was eligible for 151 party unity votes in 2009. As a Republican, Specter was eligible for 25 presidential support votes; his presidential support score was 76 percent; opposition score, 24 percent; and participation rate, 100 percent. As a Democrat, he was eligible for 54 presidential support votes in 2009.
Instructions: Click on the "CONTROLS" tab when the data finishes loading to select a view mode, switch between chambers, and locate a specific member in the graphic. This interactive chart presents four modes for exploring vote study data:
Scatter comparison: This graph combines an individual lawmaker's party unity score (indicated along the vertical axis) with his or her presidential support score (along the horizontal axis). The result is a single point on the graph that represents each lawmaker, and that helps to demonstrate their often different positions. Lawmakers who fall toward the top of the graph are more supportive of their party than those toward the bottom. Those who fall toward the right edge support the president more, and those who fall toward the left support him less. Those who fall toward the center tend to be considered centrists.
Distribution of Presidential Support: This graph shows the spectrum of positions that members of the Republican and Democratic caucuses in each chamber have in support of the president on those votes where he had a clear position. It also shows how many lawmakers fall at each point, indicating the full distribution of these so-called presidential support scores.
Distribution of Party Unity: This graph shows the spectrum of positions that members of the Republican and Democratic caucuses in each chamber have in support of their party's position on those votes that pit a majority of Republicans against a majority of Democrats. It also shows how many lawmakers fall at each point, indicating the full distribution of these so-called party unity scores.
Data table: This view presents all vote study scores in a sortable table. Click the headers to sort by any given field. You can also use the "Find Member" pulldown menu in the controls bar to locate a specific member in the table.
Last updated: Jan. 8, 2010. Editor: John Cranford, Researcher: Rachel Bloom, Interactive: Thomas Wilburn