Found via Time magazine, a report from National Journal: "Who's the Most Liberal?"
This report uses votes by politicians in Congress to figure out who wins labels as most liberal, most conservative. Surprise: John Kerry gets the most-liberal label. That actually did surprise me! Excerpt:
"Listening to her critics, you might have guessed Hillary Clinton is the farthest left of the Democrats that might run for President in 2008. In fact, Clinton wasn't even one of the top 10 most liberal Senators last year. But the true liberal of that group, according to rankings compiled by National Journal, a non-partisan public affairs magazine, is actually John Kerry. Because he was off campaigning last year, Kerry missed too many of 63 votes the magazine used to calculate its ratings for 2004. But his lifetime ranking, compiled from his entire Senate career, puts him at a 85.7 (out of 100) liberal rating, compared to a 80.7 for Clinton. While Kerry was attacked as being too far to the left in the 2004 general election, Indiana Senator Evan Bayh has the opposite problem. Bayh, with a liberal rating of only 61.7 was more conservative last year than Joe Lieberman, (69.8) who struggled to woo strong liberals in the Democratic primaries competing against Kerry and Howard Dean.
For Republicans, 2008 hopefuls Rick Santorum, Frist and Virginia Senator George Allen all had similar rankings, around 78 on the conservative scale through their Senate careers. But whatever popularity and name recognition John McCain has, being ranked the third-most liberal Republican (48.3) in the Senate last year probably won't help him in the Republican primaries. Asked about the rankings, McCain said 'over 22 years, I've been far more on the conservative side' and blamed his ranking in part on his opposition to additional tax cuts that many in his party support but he thinks will add to the deficit. Allen said 'I just vote my conscience, adding that he considers himself 'a common-sense Jeffersonian conservative.' (Never mind that the third president was a founder of today's Democratic Party."