https://legacy.voteview.com/Is_John_Kerry_A_Liberal.htm
Every congressperson and Senator between the 75th and 107th congresses ranked in terms of liberalism; a a score of 0 is the most moderate, a score of -1.000 is the most liberal and a score of 1.000 is the most conservative.
In case you’re wondering, the most liberal congressperson was William Meyer of Vermont, who served one term from 1959 to 1961. The most conservative is Ron Paul.
Good find. Though i have found it about 10 years ago. The similar info for every Congress may now be found on
www.voteview.com pages.