From the story here:
'In 2008, academics at Yale published an influential paper showing that one of the most effective ways to get voters to the polls was “social pressure.” Researchers found that registered voters in a 2006 primary election in Michigan voted at a higher rate if they received mailers indicating that their participation in the election would be publicized. The mailer that had the biggest impact included information about the two previous elections and whether the recipient and his or her neighbors participated or not. “We intend to mail an updated chart,” the mailer warned. “You and your neighbors will all know who voted and who did not.”
'Insights from the Yale study have since been adopted by several campaigns, including MoveOn, which also faced criticism when it used the tactic to turn out voters for Barack Obama’s reëlection, in 2012. Given its obsession with political science, it’s no surprise that the Cruz campaign decided to adopt the “social pressure” techniques to turn out voters in Iowa for Monday night’s caucuses.'
"The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated . . .."
