Romney, during a debate this weekend, called out Huntsman for serving as U.S. ambassador to China under President Barack Obama. Going tit-for-tat, Huntsman slammed Romney on Sunday for not putting country ahead of politics.
To be fair, the two are distant cousins.
"Probably more distant now than ever," quipped Huntsman's chief strategist, John Weaver.
Some of the angst between the two dates back to the scandal with the Salt Lake Organizing Committee, which was planning the 2002 Winter Games.
When the committee went looking for a new leader to take over from those who were forced out, Jon Huntsman's father, Jon Huntsman Sr., pushed his son. But the committee went with Romney, irking the elder Huntsman.
Over time, the relationship mended and Huntsman Sr. endorsed Romney during his 2008 presidential bid. The younger son, though, backed rival Sen. John McCain.
Huntsman previously told me that talk of such a feud between the two is "overblown" and that he laughs when he hears about some internal strife.
Kevin Madden, a senior adviser to Romney, also dismisses any personal problems.
"I don't think there's anything personal in this campaign," Madden said. "This is a campaign that is focused on issues. The contest between them is about who would be a better president."
Of course, there are other family members who are caught in the middle.
At a house party in Bedford, N.H. on Sunday night, I ran into John and Chere Romney and was intrigued by their nametags. Romneys at a Huntsman rally?
Turns out the couple is from Salt Lake City. And John Romney is an even closer cousin to Mitt Romney. But he backs Huntsman.
"I like both," he clarifies. "I'm related to Romney but I've know the Huntsmans and I really, really respect the Huntsmans."
Let's just say the family reunions this summer could be very awkward.
Thomas Burr Twitter.com/thomaswburr