[gondramB]

" I think you can pretty well assume that if she supports the Griswold decision she also supports its rationale."

Even the justices that vote together don't always have the same rational, sometimes they even issues separate opinions.

[bourbon]

Correct. But Miers saying that she supports Griswold means that she supports the majority opinion (i.e. the controlling opinion). She didn't say, "I support Black's dissent or Harlan's concurrence."