McKinnon and his wife Lucille had two sons, Clinton Daniel (Dan) and Michael Dean (Mike), and a daughter Connie.

Other Journal alumni included Tribune editor and columnist Neil Morgan and Congressman Lionel Van Deerlin.

McKinnon was first elected to the House of Representatives in 1948, defeating Republican incumbent Charles K. Fletcher, founder of Home Federal Savings and Loan.

[1] Gordon Luce, then the California Republican Party Chairman, said that he was a bright and hard-working leader that even political opponents respected.

[citation needed] His other ventures included the La Jolla Light, Coronado Journal, and radio station KSDJ (now KCBQ).

[1][2] His son Michael D. is the majority stockholder in McKinnon Broadcasting, owner of San Diego Home & Garden Lifestyles Magazine, and a former Texas state legislator (1972–1976).