Brazil's Rousseff pledges unity gov't as impeachment momentum grows

By Anthony Boadle and Maria Carolina Marcello BRASILIA (Reuters) - Brazil's President Dilma Rousseff pledged on Wednesday to form a government of national unity if she survives an impeachment vote in Congress this weekend, but the odds of that lengthened as allies continued to desert her. A stream of defections from Rousseff's coalition makes it increasingly likely she will lose Sunday’s ballot in the lower house of Congress on whether she should face trial in the Senate over accusations s