Congress has become more liberal over the last year, the Americans for Democratic Action said in a survey that gave 23 lawmakers perfect scores for their votes on about two dozen issues. The liberal group, in its annual survey, gave five senators and 24 representatives--all Republicans--scores of zero, fewer than the 15 senators and 46 representatives who were given that grade a year ago. The ADA gave the Senate an average score of 52%, up 8 percentage points from last year, with Democrats voting in agreement with the ADA an average of 76% of the time and Republicans, 25%. The average in the House was 51%, up 5 percentage points from last year. Democrats voted in agreement with the ADA 76% of the time and Republicans, 15%.