SALT LAKE CITY — The way Mike Kennedy sees it, he’s “just a plain old guy.” He’s no Mitt Romney, the millionaire Republican elder statesman and Kennedy’s opponent for the party’s nomination for Utah’s soon-to-be-open Senate seat. And he’s certainly no Ted Kennedy, the late liberal senator with whom he shares a surname but not a bloodline. Nope. Mike Kennedy’s “just a plain old guy” who “comes from dirt.” Mike Kennedy is not really plain or old. He’s a physician, and a lawyer, and a three-term state legislator, a husband and father of eight children. He’s a practicing member of...