SARAH Palin is on the verge of leaving her husband. An upcoming tell-all book by a once-loyal Palin aide contains such a damning portrayal of Todd Palin that it could cause the couple to divorce, according to American tabloid the National Enquirer. Sources say Sarah is desperately trying to discredit former confidante Frank Bailey, who plans to publish a blockbuster book titled, Blind Allegiance to Sarah Palin: A Memoir of Our Tumultuous Years. The Palins marriage was already shaky, and this book is so scathing regarding Todd that it could cause Sarah to leave him, dished one insider. This is a massive scandal and Todd had a huge part in it, according to the book. If she takes too much heat for Todds conduct, her only option may be to leave him to preserve her political career. The only love they shared was the love of Sarahs career, and everything they did was aimed at Sarahs public image. Todd and Sarah stayed together solely for political purposes. Sarah once told Bailey, 'Were not like normal couples, Frank. We dont talk. SS