When I saw that former Gov. Tim Pawlenty (R-Minn.) over the weekend unleashed a new put-down of the health care-law as “Obamneycare,” I was impressed. “Obamacare” is the Republican pejorative of choice for the measure. President Obama hasn’t been shy to remind everyone that his health-care law was inspired by the one championed in Massachusetts by then-Gov. Mitt Romney (R). So, “Obamneycare” was a clever slap, a rhetorical cluster bomb that took out two big targets at once.

But at the CNN Republican debate in New Hampshire last night, Pawlenty pulled back from using his powerful creation, as Jennifer Rubin and E.J. Dionne noted. Why?

“And you don’t want to address why you called Gov. Romney’s [health-care law] ‘Obamneycare?’” John King asked.

“Well, the issue that was raised in a question from a reporter was what are the similarities between the two,” Pawlenty said, “and I just cited President Obama’s own words that he looked to Massachusetts as a blueprint or a guide as he designed Obamacare.”

Naturally dissastisfied with that nonanswer, King pressed Pawlenty a little harder. “If it was ‘Obamneycare’ on ‘Fox News Sunday,’” he asked, “why isn’t it not ‘Obamneycare’ standing here with the governor right there?”

“President Obama is the person who I quoted in saying he looked to Massachusetts in designing his program,” Pawlenty said. “He’s the one who said it was a blueprint and that he merged the two programs and so using the term ‘Obamneycare’ was a reflection of the president’s comments that he designed ‘Obamacare’ on the Massachusetts health care plan.”

Pawlenty is way down in the polls among GOP primary voters. He’s pushing hard to raise enough cash to be a viable alternative to frontrunner Romney. So why on earth would Pawlenty run away from his masterstroke of an attack line? If his ultimate goal is to be the other half of a Romney ticket, perhaps he realized that his brilliant, cutting remark cut a little too deep.