Similarities in Position

The senatorial voting patterns of Hillary Clinton, John McCain, and Barack Obama
By Dave Tufts, davetufts@gmail.com, March 2008

Executive Summary: Analysis of Clinton, McCain, and Obama’s Voting Histories

Barack Obama is the least responsible of the three, missing 18% of his votes. Hillary is the most responsible, only missing 9% of her roll calls.

Clinton and Obama cast the same vote 92% of the time.

In 299 opportunities, McCain and Clinton voted the same almost half the time.

The three candidates were all present for the same roll call 191 times. 29% of the time they all voted the same way — either all for or all against the issue at hand.

Before 2005, McCain and Clinton voted the same 73% of the time. Since 2005, McCain’s voting record has changed dramatically. See Afterward

Technical details and comments available on my company’s blog

VoteSmart.org has compiled the complete voting records for all member of congress. As of March 2008, the three remaining likely presidential candidates are all senators, making it easy to compare their records.

Analyzing Clinton, McCain, and Obama’s records, we see how often each of senator missed a vote and how similar their voting records are.

When analyzing similarities between two candidates, I only used roll calls were both candidates cast a vote. For example in October 2001, Clinton voted for bill number HR 3162, USA Patriot Act of 2001, but Obama did not cast a vote (he wasn't in the US Senate yet). Therefore, that issue was not taken into account when comparing similarities in Clinton and Obama’s voting records. However in 2006, both Clinton and Obama cast a vote on bill number HR 3199, USA PATRIOT and Terrorism Prevention Reauthorization. Since both senators voted on (and in this case for) reauthorizing the Patriot act, that roll call was factored into the similarity equation for Clinton and Obama.

Barack Obama

Total Opportunities Jan 2005–Present Actual Votes Cast Missed Votes Attendance %
255 210 45 82%
Barack Obama and John McCain voted the same on:

Barack Obama and John McCain voted on the same issue 189 times. Of those roll calls, they voted similarly on 60 issues.
Barack Obama and John McCain are 31% similar

Barack Obama and Hillary Clinton voted the same on:

Barack Obama and Hillary Clinton voted on the same issue 210 times. Of those roll calls, they voted similarly on 198 issues.
Barack Obama and Hillary Clinton are 94% similar

John McCain

Total Opportunities Jan 1995–Present Actual Votes Cast Missed Votes Attendance %
635 540 95 85%
John McCain and Barack Obama voted the same on:

John McCain and Barack Obama voted on the same issue 189 times. Of those roll calls, they voted similarly on 60 issues.
John McCain and Barack Obama are 31% similar

John McCain and Hillary Clinton voted the same on:

John McCain and Hillary Clinton voted on the same issue 299 times. Of those roll calls, they voted similarly on 141 issues.
John McCain and Hillary Clinton are 47% similar

Hillary Clinton

Total Opportunities Jan 2001–Present Actual Votes Cast Missed Votes Attendance %
368 335 33 91%
Hillary Clinton and Barack Obama voted the same on:

Hillary Clinton and Barack Obama voted on the same issue 210 times. Of those roll calls, they voted similarly on 198 issues.
Hillary Clinton and Barack Obama are 94% similar

Hillary Clinton and John McCain voted the same on:

Hillary Clinton and John McCain voted on the same issue 299 times. Of those roll calls, they voted similarly on 141 issues.
Hillary Clinton and John McCain are 47% similar

All 3 Candidates

All three candidates voted the same on:

All three candidates voted on the same issue 191 times. Of those roll calls, they voted similarly on 57 issues.
They are all 29% similar

Afterward: McCain’s Slide Away From The Democrats

Looking over the data, two things popped out:

  1. Clinton and Obama have voted almost identically since Obama joined the senate in January of 2005.
  2. McCain and Clinton’s records are fairly similar — about 50% of the time they vote the same. But McCain and Obama offer much more of a contrast — they only vote the same about 30% of the time.

This made me think that Clinton’s voting pattern has moved away from McCain in recent years. I was wrong.

After comparing both McCain and Clinton to a control subject, it’s clear that McCain is the one who dramatically changed his voting pattern.

For a control Senator, I picked Ted Kennedy. He was in office for the entire date range in question. He had no aspirations of running for President or appeasing anyone enough to change his voting pattern. It doesn’t matter if the control is liberal, centrist, or conservative. The only important quality is consistency, and Ted Kennedy seems to have that.

Candidates 2001–2005 2005–2008
McCain & Clinton 73% Similar 76 identical votes, 109 opportunities 34% Similar 65 identical votes, 190 opportunities
McCain & Kennedy 62% Similar 67 identical votes, 107 opportunities 31% Similar 61 identical votes, 196 opportunities
Clinton & Kennedy 88% Similar 98 identical votes, 111 opportunities 90% Similar 201 identical votes, 223 opportunities

Comparing McCain to either Clinton or Ted Kennedy shows that McCain changed dramatically. This change isn’t in just 2 or 3 major issues. Both comparisons cover almost 300 votes.

While McCain’s consistency bounced 30+ percentage points in 2005, Hillary Clinton’s record proved to be the consistent one.

What made McCain’s voting record change so drastically?

Add comments and read about the technical details on my company’s blog