Al Dugan says he’s an analytical, data-driven guy, the result of decades in the insurance field. Raised in New Orleans, he attended Louisiana State University before moving to the Bay Area; here he spent decades—including 24 years as an executive—underwriting marine and land cargo. He held major complex accounts with companies like Apple and Amazon, and traveled the globe. 

Mr. Dugan was relatively uninvolved in civic life in Novato, where he has lived in the…