Keith Burgess-Jackson faults the New York Times for saying that "nearly 70 percent of Americans [said] in a recent Harris poll that they would oppose Judge Alito's confirmation if they thought he would vote against constitutional protection for abortion rights." The poll itself, he points out, asked "If you thought that Judge Alito, if confirmed, would vote to make abortions illegal, would you favor or oppose his confirmation?," which is analytically quite different: A vote against constitutional protection for abortion rights is a vote to return the matter to the states, not to make abortions illegal. (Even if one focuses on the practical implications, I doubt that more than a handful of states would even make all first-trimester abortions-on-demand illegal, though many states might make many second-trimester abortions illegal.)
But it turns out that the poll results for these two questions aren't vastly different. Prof. Burgess-Jackson writes that "There is no evidence that 70% of the American people oppose overruling Roe v. Wade," but in fact a Dec. 2005 NBC News poll that asked, "The Supreme Court's 1973 Roe versus Wade decision established a woman's constitutional right to an abortion, at least in the first three months of pregnancy. Would you like to see the Supreme Court completely overturn its Roe versus Wade decision, or not?" yielded 30% overturn, 66% not overturn -- not that far off the 31%-69% result reported by the Harris Poll. A Nov. 2005 poll reports a lesser margin, 32% to 57%; but the big picture remains not vastly off of what the Harris poll reports. (The Dec. 2005 and Nov. 2005 polls misdescribe Roe as focusing chiefly on the first three months; in practice, Roe also protected abortions in the following three months, though with some modest regulations; Casey then cut that back to abortions before viability; but this error, while significant generally, is not that important for purposes of this particular post.)
So, yes, it's right to fault the New York Times for its imprecise reporting, and for that matter Harris for surveying about a hypothetical scenario that is extremely unlikely (Alito voting to actually make abortions illegal). But the practical effect of the error is actually not that great, and there is indeed substantial evidence that a large majority, quite possibly nearly 70%, of the public opposes -- whether rightly or wrongly -- a total overruling of the Roe/Casey constitutional right to abortion.