Mitt Romney is on the hunt for a vice presidential candidate, and if his years running Bain Capital are any indication, he might be looking for a version of himself. In his roughly 25 years at Bain, Romney tended to hire mini-Mitts — smart, ambitious, clean-cut and a little awkward, according to those who dealt closely with the men. Romney built the private equity firm, a spinoff of the consulting firm Bain & Co., from the ground up in the mid-1980s, bringing on several people who would help him turn it into an investment giant. “First-rate brain power, first-rate analytical...