Gerald Rudolph Ford, Jr., was never a senator. George Herbert Walker Bush was never a senator but LOST two Senate races: 1964 and 1970, to Yarborough and Bentsen, respectively. HST was of course a U.S. senator but not well-known until the convention tapped him in 1944.
"Gerald Rudolph Ford, Jr., was never a senator"
You're right, he was a representative, I forgot about that. My point remains though... there's just no statistical justification for saying that senators can't get elected. There aren't nearly enough examples to confirm tha theory since most Senators that got elected served as VP as well. If you take those out, of course you're going to get an odd result.
If you make enough qualifiers you can find an omen in anything. I've never been in a car accident on a tuesday in march... so what? Does that mean I can drive like a maniac the first Tuesday of next March?