And McCain is VERY conservative.
Saw this at Electoral-vote.com (a generally fantastic site). They did a composite ranking of 7 Liberal Interests Groups (ACLU, Americans for Democratic Action, Children's Defense Fund, League of Conservation Voters, NAACP, NARAL, and SEIU) to determine who is the most liberal/most conservative.
The results were surprising. Clinton is the 38th most liberal, Obama 42nd. And John McCain: 5th most conservative. Keeping company with Oklahoma Global Warming denier James Inhofe and warner of the threat of lesbian debauchery, Tom Coburn.
One caveat: this is only 7 interest groups, and using different ones could give you a different picture. And they will coming out with a conservative composite soon. Also some surprising tidbits on Lieberman.
Here's the link, if you go, also check out the Clinton/Obama vs. McCain maps.
http://www.electoral-vote.com/