Hmmm, having some difficulties with this computer. My first message didn't post. I'll try again...

"The Missouri Compromise of 1820 was rendered mute and invalid by the Compromise of 1850, which superceded it."

Not completely. The Missouri Compromise was still on the books and the standard (one might say) for the admission of states from the western territories. Stephen Douglas, I believe, did try to argue that the Compromise of 1850 had already nullified the Missouri Compromise, but few people were convinced by this logic. Most recognized that the Compromise of 1850 had specifically averted a potential crisis by dealing with new territory brought about by the Mexican War, rather than established any new terms for future admissions.

Had the Missouri Compromise been "rendered mute and invalid" by the Compromise of 1850, the Kansas-Nebraska bill would not have been as traumatic to the Democratic Party and the nation as it was. The virtual repeal of the Missouri Compromise by Douglas' bill literally fractured northern Democratic affiliations, spurred the birth and growth of the Republican Party, and set off such a wave of protest that Douglas remarked he could travel from the east coast back to Illinois by the light of his burning effigies. Indeed, his attempt to sell the Kansas-Nebraska Act to the country was likely his most difficult and most significant political act.

"The United States Supreme Court Declared that the Admission of States to the Union as either Free or Slave States as a basis for admission was Unconstitutional in the Dred Scott v Sanford Case."

Yes, I agree, the Supreme Court decided that Congress had no authority to legislate against slavery in the territories. But, that was in 1857...three years after the Kansas-Nebraska bill passed through Congress. In your earlier post you said that there were two Supreme Court decisions on this matter, the first of which supposedly revoked the Missouri Compromise before Dred Scott v. Sanford. Which other case are you referring to?

"Hence the Compromise of 1850 and the Kansas Nebraska Act were rendered as being questionable law by the Dred Scott v Sanford decision of 1857."

How was the Kansas-Nebraska Act challenged by Dred Scott?