Mystery solved? A speechwriter for Sen. John McCain&amp;#8217;s 2008 presidential election has been widely identified as the author of the controversial &amp;#8220;O: A Presidential Novel.&amp;#8221; According to Time&amp;#8217;s Mark Halperin, Mark Salter crafted the novel set during the presidential race of 2012 that&amp;#8217;s caused a commotion in both the literary and political worlds since its [...]