As Cruz leads in Iowa and other states putting Trump in second place, Hamburger provides an exceptional look inside the Cruz campaign. Cruz's campaign manager says rules of the past no longer apply, in a changing voter environment pushing out establishment candidates and with the digital media tools now available. Data analysis and use of methods such as "psychographic targeting" to tailor appeals to voters based on what appeals to them using Facebook data on likes are being used by the Cruz campaign. Cambridge Analytica, a firm financed by hedge fund executive Robert Mercer, a Cruz supporter, has built an effective data gathering operation of potential Cruz supporters among evangelicals. This has helped the Cruz campaign recruit pastors in Iowa, and in the U.S. for the Cruz campaign. It also helps in micro efforts such as home calls made by supporters, and in "geofencing" or sending emails and messages to a particular building or physical location such as a gathering of the National Rifle Association, or Republican Jewish Coalition. A mobile app "Cruz Crew" is another aspect of the digital effort to organize efforts of supporters and volunteers....