The fateful question came from a tax lawyer, in a room filled with dozens of them. It came at the end of a Friday morning panel, on the second day of the American Bar Association tax section’s big annual meeting at the Grand Hyatt hotel in Washington D.C. The moderator had announced that it would be the panel’s last question. “Lois, a few months ago there were some concerns about the IRS’s review of 501(c)(4) organizations, of applications from tea party organizations,” Celia Roady, a veteran tax lawyer, asked Lois Lerner, head of the IRS’ tax-exempt organizations division, a few...