That’s not what the Buckley Rule says. If it were, he could not have supported either Barry Goldwater or himself when he ran for mayor. The test is “viability” which is a different thing from “electability.”
When you opt for “electability”, you usually lose.
You’re definitely over the target TBP!
Great article on “The Buckley Rule” from someone who knows the complete history of it.
http://www.nationalreview.com/node/340485/print