Mary Cheney, the former vice president's openly gay daughter, wrote on Facebook that her sister was "on the wrong side of history" in regard to gay marriage after Liz, a candidate for U.S. Senate in Wyoming, publicly defended her opposition. Mary's longtime partner Heather Poe has also criticized Liz Cheney on her Facebook page.
The back-and-forth has soured the sisters' relationship. Mary Cheney said that she does not plan to see her sister at Christmas although the entire family is expected to gather for the holidays in Wyoming.
Dick Cheney said he wouldn't discuss the family feud any further and said the dispute was "obviously a difficult thing for a family," according to ABC News.