Supervisory Special Agent Gary Shapley and Special Agent Joseph Ziegler are longtime IRS employees who came forward as whistleblowers to accuse the agency of allowing Hunter Biden to skate on serious tax charges. Here, the two explain why they want to be a part of a civil suit the president’s son filed against the IRS — to defend strongly what the government won’t. Like most whistleblowers, we did not wake up one morning and decide to pick a fight. We simply tried to do our jobs like always, even in the face of increasing resistance from a system that did...