Opposition leaders Mir Hussein Mousavi, Mehdi Karroubi and former president Mohammed Khatami have all challenged Mr.Ahmadinejad's legitimacy, arguing that he won re-election through fraud and vote-rigging.

VOA: standard.2009.08.28

The 60-vote advantage is also important because it will make it far more difficult for Republicans to block passage of bills through a filibuster, in which senators tie up the floor in long speeches to prevent a vote.

VOA: standard.2009.06.30