It is not the same as agreeing with the lower court - AIUI if they heard it and ruled, the scope of the decision for purposes of precedent would be* "every cour

It is not the same as agreeing with the lower court - AIUI if they heard it and ruled, the scope of the decision for purposes of precedent would be* "every court" (though not necessarily every case), while declining to hear it does not change the scope or outcome of the prior ruling. * - as with everything in the legal system, there are exceptions and fuzzy lines, and IANAL.