As counsel for the Warren Commission, Arlen Specter described a "magic bullet" that changed America. Four decades later as a U.S. senator, Specter is providing another history-altering magic bullet - one Democrats will either fire off in a starting gun, or use in their suicide.

By leaving the Republican Party this week, the five-term Pennsylvania lawmaker eliminated the last Democratic rationale for inaction: the Senate filibuster. With Minnesota Democrat Al Franken expected to be seated soon, and now with Specter, Democrats will have the 60 Senate votes needed to overcome all parliamentary obstructions.

This legislative magic bullet will force Democrats to fulfill their policy promises and commence an era of dominance, or fail and get annihilated at the polls.

No longer can they blame Republicans for stopping bills to reform health care, tax, defense and trade policy. In command of the White House, the autocratic House of Representatives, and soon a filibuster-proof Senate, Democrats will have total authority to do whatever they want, and no scapegoat to fault. That means, as ABC News' Rick Klein said, "This is Democrats' turn to govern, no excuses" - and it means we're about to find out whether their pledges were genuine.

David Sirota, Common Dreams