Deep Bench to Fight RFKBeing the U.S. Secretary of Agriculture is usually a pretty good job. It involves doling out billions of dollars, the constituency is dominated by courteous country people, and controversies tend to be minor. The person serving the longest in any Cabinet position was James “Tama Jim” Wilson at USDA for 16 years. Current USDA Secretary Tom Vilsack will have served in the position for 12 years. Henry A. Wallace served as USDA chief for eight years before being elevated to Vice President. Officially, the position is mid-tier in the presidential line of succession. But it is technically oriented, and the weakest secretaries have been those ill-suited to the job. Per Dave Juday’s discussion of who might be the next US...