Six years ago this month, Jim Karger left the firm he founded. He’d known for some time that he needed to change his life. Work pressures had led to a ritual he found appalling: After leaving his office, he called his wife, Kelly, a few blocks from home and asked her to get his Wild Turkey and water ready so she could hand him the drink as soon as he walked through the door.

By worldly measures, Karger was a successful attorney — a partner in Dallas’ Karger, Key, Barnes & Springer, billing $300 an hour and earning $500,000 a year. For about two decades, Karger says he had a thriving law practice and an undefeated record in heading off unionization drives at companies. His unorthodox approach to his work involved persuading companies to identify the mistakes that sparked employees’ desires to unionize and then fix them.