Rasmussen. 1/9. Likely Republican primary voters. MoE 5% ( results)
This would be a best-case scenario -- a narrow Romney victory would keep him in the race, but tainted from the possible interference of mischief-causing crossover Democratic votes.
But in short, with nothing of relevance happening on the Democratic side, Michigan Democrats have a chance to further ensure clusterfuckery on the GOP primary, thus prolonging their debilitating civil war.