It is an interesting point you offered, because the Kentucky Resolutions were brought about in direct response to the Alien and Sedition Acts, an act of the federal Congress which Jefferson, in the same resolution, called upon the authority of the federal Constitution to verify its invalidity. In addition to citing the tenth, he also cited the first when he said, And that in addition to this general principle and express declaration, another and more special provision has been made by one of the amendments to the Constitution, which expressly declares, that 'Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof, or abridging the freedom of speech or of the press': thereby guarding in the same sentence, and under the same words, the freedom of religion, of speech, and of the press: insomuch, that whatever violated either, throws down the sanctuary which covers the others, arid that libels, falsehood, and defamation, equally with heresy and false religion, are withheld from the cognizance of federal tribunals. That, therefore, the act of Congress of the United States, passed on the 14th day of July, 1798, intituled 'An Act in addition to the act intituled An Act for the punishment of certain crimes against the United States,' which does abridge the freedom of the press, is not law, but is altogether void, and of no force."
That being said, we must recognize that we're talking about two different animals. There is a vast difference between insisting the federal government has no authority to abridge the freedom of the press while supporting the argument by the Constitution, and claiming that murder is prohibited by the Constitution. It cannot be said with any credibility that because a person supports one claim that he must support the other. They are not that closely related, given the context of the Resolution and what is happening in Oregon and the Justice Department. You'll get no argument from me that Jefferson would be most displeased at the power the federal government has usurped since his day (Chief Justice John Marshall, the perpetrator of the Barron case, was Jefferson's chief antagonist, perhaps even moreso than Alexander Hamilton), and I would agree with him. That doesn't mean, however, that he would necessarily support your claim any more than it means that because he wrote the Declaration of Independence or that he didn't like Marshall that he would support mine. Unless either of us can find direct statements from Jefferson to the effect of whether or not murder was prohibited under the Constitution and simply ceded to the states, as they were considered the entities most capable of the task, he must be considered effectively neutral on the particular issue, while we still may be able to cite his words for relevant subpoints.
It seems, instead, your argument must be either be against the constitutionality of the Controlled Substance Act (provisions of which I may agree with you if you did), which seems to cede some judgement to those charged with enforcing it, or the definition of "due process," both of which I'd be happy to debate. However, I should point out that the Attorney General's basis for his actions do not in fact prevent all assisted suicide, only that which requires the use of controlled substances to kill another human being. I shall provide an amendment to that basis in a moment.
Even if you find scholars willing to apply the bill of rights to State action you have not attempted to show how it is legitimately applied to the actions of individuals, which was my original contention before the debate was sidetracked.
I actually have attempted it, but if you'll forgive me, I'm not certain that those attempts were directed at you. It really comes in two points. First, as was argued in the Barron case, the amendment concerns the life and liberty of the citizen, not those who would deprive the citizen of those rights -- states, federal government, corporations, or individuals. There was no need for the federal government at the time to interfere as there were no state laws, to my knowledge (and if you could find one allowed to stand that would surely bolster your case), that allowed physician-assisted suicide, and murder was universally forbidden and adequately punished by the state governments. It wasn't that assisted suicide never happened, but that common law was already strictly against it, and even had quite harsh penalties for not only the one assisting, but for the person committing suicide. The latter penalties were withdrawn by the colonies because they thought it unfair to punish the family of the person committing suicide.