“She hopes that all parties can rally together in opposition to this grave threat.” U.S. Sen. Hillary Clinton canceled her appearance at a demonstration against the president of Iran after learning Republican vice presidential candidate Sarah Palin will be there, a Clinton aide said on Wednesday. A group of Jewish organizations had said both Palin and Clinton would speak at the protest near the United Nations on Monday against Iranian President Mahmoud Ahmadinejad, who has said Israel should be wiped off the map.