No, I believe that they think that Dred Scott is code for Roe v. Wade and indicates that Bush would nominate a judge to help overturn that decision. For example, you can find the following excerpt on the site of OR/OSA (Operation Rescue / Operation Save America) at http://www.operationsaveamerica.org/walk/live/pressReleases.html:
A broken set of the Ten Commandments, a baby killed by abortion, a white horse (Judgment) and donkey (Mercy), will bring God’s message to St. Louis.
Rev. Flip Benham, Director of Operation Rescue / Operation Save America will join Angela and Daniel Michael of Small Victories Ministry at the Historic Old Courthouse, where the infamous Dred Scott case was heard. "The Supreme Court was wrong in the Dred Scott Case that declared our black brothers and sisters non-human and in Roe v. Wade that declared innocent little boys and girls non-human. Judgment and Mercy are calling America to repent." Rev. Flip Benham, National Director, OR/OSA
As the excerpt says, the Dred Scott case was heard in St. Louis, the same place where Bush made his remark. This, of course, may be a coincidence. In any case, many in the pro-life movement equate Dred Scott and Roe v. Wade.
And the truth is that Roe v. Wade is very much like Dred Scott and that those upholding it, like Taney upholding slavery, are biased in favor of what is ultimately an insupportable outcome and thesis. Killing the innnocent in the womb is as morally insupportable as slavery was.