The Secular Coalition for America has released its scores for members of Congress. The scores are supposed to reflect a legislator's commitment to the separation of church and state. For the Senate, few of the votes on which people are rated relate directly to that. For example, Senators are rated on selected judicial confirmation votes (for both cloture and to confirm), the cloture vote on the federal Marriage Amendment and the Stem Cell Enhancement Act. You can make the case that these reflect one's commitment to a certain notion of separation, but it's attenuated. Legislative ratings are always imperfect, but one could cast a vote on all of these without regard to any view of the relation between church and state.
In any event, our "maverick" Senator fangled, as is generally the case on all measures of adherence to the agenda of the left, scored a "perfect" 100.
On the House side, there were votes that fairly measured a legislators hostility to, or refusal to accommodate, religious perspectives. No Wisconsin legislator scored 100 (Tammy Baldwin apparently whiffed on DoD funding for the Boy Scouts), but three of our 4 GOP members scored what is truly a perfect 0.
As is generally the case, Sensenbrenner was more of a "maverick" than Feingold, scoring a 20.