"The Perry Truth Team awards a 10.0 on the flip-flop scale to Mitt Romney for his less-than-24-hour switch on supporting right-to-work reforms enacted by Ohio Governor John Kasich," said Perry's statement.

Ironically, Perry's social-media efforts mirror those of an unlikely ally — the Democratic National Committee. The DNC has urged its supporters to tag Romney flip-flops with a #whichmitt hashtag, and launched a corresponding website and YouTube channel to highlight instances where Romney has shifted position.

The Obama reelection campaign has also Romney's shifting positions as a potential vulnerability, hammering the former Massachusetts governor for political opportunism.

"Across the political spectrum, people have the same question: If you are willing to change positions on fundamental issues of principle, how can we know what you would do as president? How can we trust who you would be?” said Obama campaign strategist David Axelrod.

Republican strategists have long viewed Romney's shifting positions on issues — a by-product of transitioning from a job as governor of a solidly blue state to the national stage — as an area of weakness. But while Romney was hammered during his 2008 presidential campaign for equivocating, he has largely been able to avoid the narrative this cycle.