Republican Gov. Scott Walker is using his new book to renew his criticism of 2012 GOP presidential nominee Mitt Romney and raise his own national profile as a reformer who took on public sector unions and won. Walker’s book provides a detailed account of his 2011 battle against public unions, the campaign he won against their efforts to recall him, and his unhappiness with Romney and other Republicans he says didn’t learn the lessons of his political victories. The volume could set the stage for Walker’s own candidacy in the future. The Associated Press on Friday obtained a copy of...