The Washington Post reports:
[Mitt Romney] also criticized people who choose not to get married because they enjoy the single life.
"It seems that Europe leads Americans in this way of thinking," Romney told the crowd of more than 5,000. "In France, for instance, I'm told that marriage is now frequently contracted in seven-year terms where either party may move on when their term is up. How shallow and how different from the Europe of the past."
If this quote is accurate and in context, then it does seem more than just a screw-up caused by being tired -- Romney went out of his way to say this, and must have had at least some opportunity to reflect on it and to realize that it bears a little more checking. So it seems to me this reflects worse on him than the 10,000-death-toll (an error in one number, and one that was apparently fairly promptly corrected) misstatement by Obama.