Blow was referring to a point in the debate where the candidates were discussing birth control, gay marriage and families. During the debate, Romney spoke of his belief that children were better off in homes with mothers and fathers.
On Friday, Blow issued the following apology via the same Twitter feed:
"Btw, the comment I made about Mormonism during Wed.'s debate was inappropriate, and I regret it. I'm willing to admit that with no caveats."
Blow has been a columnist for the New York Times since 2008, and has often been critical of conservatives.
A Buzzfeed.com article described Mormon garments as "...a rough equivalent of Jews' yarmulkes or tzitzit."
Buzzfeed's article also noted:
"It's difficult to imagine a Times writer making a similar joke about a Jewish politician."
Romney used a little sarcasm to brush off the tweet
during a radio show on Thursday, saying, "I guess we're finding out for the first time that the media is somewhat biased."