This is a term I coined in an article on the Huffington Post in 2011, to describe Democrats who switched parties to support Ron Paul, my favored candidate, for the presidency. The article made the progressive case (pro-peace, pro-civil rights, anti-cronyism) for this Republican candidate, whom the media were calling at the time (falsely) "ultra-conservative". The article went viral and almost overnight created the biggest coalition for Ron Paul's candidacy. “Blue Republican” remained the largest single coalition for him until the convention. And it comprised largely folks from the other side of the aisle.
This effort, which resulted in about 60 or 70 media interviews, launched me in political psychology and communications.