1) Oops, Dred scott, not Derd scott.

2) Slavery and many issues dealing with it were outlined in the constitution, making federal cases dealing with it plausible.

3) Bad comparison on my part. Dred Scott was an idiotic decision, whereas Roe V Wade was a case which should never have gotten to the federal bench, as the answer is clearly contained in the 10th amendment. However, the courts have been trampling on states rights for a number of decades now, so it doesn't shock me in the least.