COLUMBIA, South Carolina (CNN) -- The "stool" is a staple of Mitt Romney's campaign pitch. To be successful, he argues, Republicans need a strong message on the military, the economy, and families.

So it was no surprise when the former Massachusetts governor raised the "stool" theme Wednesday in a breakfast with state GOP chairmen, and then later in a brief interview with CNN.

But this time the way he delivered the lines seemed a bit more pointed, leaving some in his audience convinced it was directed at Rudy Giuliani's argument that he is the party's best hope in the general election.

In the conversation with CNN, Romney said:

"Republicans win when they have a stool, if you will, with three legs. Strong military, strong economy and strong family. And it's just not going to be possible to have a nominee who can't speak on all three topics with passion and with a record that supports their capacity to generate a strong family, a strong military and a strong economy."

The latter half could be interpreted as a suggestion the twice-divorced Giuliani might not be as strong a candidate as a man married for 38 years.