By John Cranford and Rachel Bloom, CQ Staff

Congressional Quarterly has studied the voting behavior of members of Congress since 1953 to assess how often lawmakers stick with members of their own caucus on votes when the two parties divide and how often they back the president on votes where he has a clear position.

CQ has completed a study of all roll-call votes during President Bush’s two terms — up to Congress’ Oct. 3 recess. This unique look at the way lawmakers voted over an entire presidency underscores the high level of Capitol Hill partisanship that has been a hallmark of the period, and shows that Republican support for President Bush generally was quite high, while Democratic support was quite low in the House and limited in the Senate.

The searchable table shows both party unity and presidential support scores over the entire Bush presidency for individual lawmakers who are currently serving in the 110th Congress. It also flags the races CQ Politics has determined will be competitive on Election Day.

• See all lawmakers’ scores.

Vote Categories

Party Unity: This analysis looks at all roll-call votes where an absolute majority of one party voted against an absolute majority of the other party. There were 2,731 such votes in the House during the period (52 percent of the total) and 1,509 such votes in the Senate (58 percent).

On average, House Democrats voted with their caucus on such party unity votes 93 percent of the time over the period, while Republicans were unified 92 percent of the time. In the Senate, Democrats stayed united on 91 percent of party unity votes, while Republicans voted together 90 percent of the time.

Presidential Support: This analysis uses all votes where the editors of Congressional Quarterly determined that President Bush had taken a clear position prior to the vote. There were 454 such votes in the House during the period (9 percent of the total) and 569 such votes in the Senate (22 percent).

On average, House Republicans supported Bush on 80 percent of such votes and Democrats supported the president on just 20 percent. In the Senate, where votes on confirmations tend to elevate presidential support scores, Republicans voted with Bush 88 percent of the time, and Democrats gave him their support on 51 percent of the relevant votes.

Lawmaker Scores: Scores are based only on the votes each member actually cast, so missing a vote does not penalize a lawmaker by lowering his or her score. Scores are rounded to the nearest whole percentage point, although rounding is not used to increase any score to 100 percent or to reduce any score to zero.

Footnotes

Party unity scores for those lawmakers who changed political parties during the period may fail to fully account for their current position, since the scores show how often these members supported their current party, regardless of their past affiliation.

Rep. Rodney Alexander , R-La., was a Democrat until Sept. 7, 2004, and Rep. Virgil H. Goode, Jr., R-Va., was an independent until Aug. 1, 2002. Sen. Joseph I. Lieberman , I-Conn., was a Democrat until Jan. 4, 2007. Lieberman and Sen. Bernard Sanders , I-Vt., are treated as if they were Democrats because they caucus with that party.