The phrase doesn't appear in Merriam-Webster's online dictionary. Dictionary.com is stumped, but suggests an alternative spelling: "shovelhead." The Oxford English Dictionary, final arbiter of all word arguments that it is, offers no shovel-ready listing, either.Read more and dig deeper yourself.
Could this be a made-up word? If so, who made it up, and how did it end up in the mouth of the next leader of the free world?
Deeper digging is required.
Speaking of made-up words, blogpourri is one too!