The official behind the IRS' conservative nonprofit targeting scandal, Lois Lerner, was friends with the Wisconsin regulator who targeted Wisconsin Gov. Scott Walker's conservative aides and allies. Lerner and Kevin Kennedy, director of the Wisconsin Government Accountability Board, were friends for 20 years and traded emails on campaign finance, politics, and personal matters between 2011 and 2013, emails obtained by the Wall Street Journal reveal. That was the same time frame the IRS increased its harassment of conservative groups and Wisconsin prosecutors conducted a secret John Doe probe of Walker's allies, raising the troubling question of whether they coordinated their...