The historical and political context are important here, as Biden's support for the bill will come into sharp relief during the primaries, as he and Bernie are the only Democratic candidates who were in Congress when it passed. Between 1960 and 1990, the U.S. experienced a mass crime wave, with violent crime increasing more than 350% during this period. Support for tougher criminal laws were not limited to white politicians but spanned the racial and political spectrum. African-Americans were hit particularly hard: from 1976 to 2005, they were 47% of murder victims. During a two-year span in the midst of the crack epidemic, D.C. saw 500 kids shot and stabbed.

The country is now fairly safe, especially when compared to the 60s/70s/80s. It is thus all too easy to pass judgment on Biden for supporting the 1994 crime bill. Politically, Democrats should be more thankful. Crime was one of the most salient issues on the national scene and played an important role in the election of Nixon 1968 and the humiliating landslide defeats of McGovern 1972, Carter 1980, Mondale 1984, and Dukakis 1988. Americans did not trust the national Democratic Party to keep them safe and saw them as weak on crime, coddling the criminals rather than protecting the victims. During this period, the Republican nominee not only crushed it with suburban voters but did respectably well in urban areas, routinely getting 30-35% of the vote in NYC. The dramatic reduction of crime during the Clinton presidency made the Democrats palatable to suburban voters and strengthened their grip on the major cities, resulting in a re-alignment that has made California, Illinois, Maryland, New Jersey, New York, Connecticut, untouchable for the Republicans.

(http://www.autoadmit.com/thread.php?thread_id=4271005&forum_id=2#38301465)