Historical Reminder (black precedent matters):

Essay on The Trial by Jury, Lysander Spooner, 1852

"The trial by jury," then, is a "trial by the country" - that is, by the people - as distinguished from a trial by the government.
It was anciently called " trial per pais" - that is, "trial by the country." And now, in every criminal trial, the jury are told that the accused "has, for trial, put himself upon the country; which country you (the jury) are."
The object of this trial " by the country," or by the people, in preference to a trial by the government, is to guard against every species of oppression by the government. In order to effect this end, it is indispensable that the people, or "the country," judge of and determine their own liberties against the government; instead of the government's judging of and determining its own powers over the people. How is it possible that juries can do anything to protect the liberties of the people against the government, if they are not allowed to determine what those liberties are?
Any government, that is its own judge of, and determines authoritatively for the people, what are its own powers over the people, is an absolute government of course. It has all the powers that it chooses to exercise. There is no other - or at least no more accurate - definition of a despotism than this.
On the other hand, any people, that judge of, and determine authoritatively for the government, what are their own liberties against the government, of course retain all the liberties they wish to enjoy. And this is freedom. At least, it is freedom to them; because, although it may be theoretically imperfect, it, nevertheless, corresponds to their highest notions of freedom.
To secure this right of the people to judge of their own liberties against the government, the jurors are taken, (or must be, to make them lawful jurors,) from the body of the people, by lot, or by some process that precludes any previous knowledge, choice, or selection of them, on the part of the government. This is done to prevent the government's constituting a jury of its own partisans or friends; in other words, to prevent the government's packing a jury, with a view to maintain its own laws, and accomplish its own purposes.
It is supposed that, if twelve men be taken, by lot, from the mass of the people, without the possibility of any previous knowledge, choice, or selection of them, on the part of the government, the jury will be a fair epitome of "the country” at large, and not merely of the party or faction that sustain the measures of the government; that substantially all classes of opinions, prevailing among the people, will be represented in the jury; and especially that the opponents of the government, (if the government have any opponents,) will be represented there, as well as its friends; that the classes, who are oppressed by the laws of the government, (if any are thus oppressed,) will have their representatives in the jury, as well as those classes, who take sides with the oppressor - that is, with the government.
It is fairly presumable that such a tribunal will agree to no conviction except such as substantially the whole country would agree to, if they were present, taking part in the trial. A trial by such a tribunal is, therefore, in effect, "a trial by the country." In its results it probably comes as near to a trial by the whole country, as any trial that it is practicable to have, without too great inconvenience and expense. And as unanimity is required for a conviction, it follows that no one can be convicted, except for the violation of such laws as substantially the whole country wish to have maintained. The government can enforce none of its laws, (by punishing offenders, through the verdicts of juries,) except such as substantially the whole people wish to have enforced. The government, therefore, consistently with the trial by jury, can exercise no powers over the people, (or, what is the same thing, over the accused person, who represents the rights of the people,) except such as substantially the whole people of the country consent that it may exercise. In such a trial, therefore, "the country," or the people, judge of and determine their own liberties against the government, instead of the government's judging of and determining its own powers over the people.
But all this " trial by the country" would be no trial at all "by the country," but only a trial by the government, if the government could either declare who may, and who may not, be jurors, or could dictate to the jury anything whatever, either of law or evidence, that is of the essence of the trial.
If the government may decide who may, and who may not, be jurors, it will of course select only its partisans, and those friendly to its measures. It may not only prescribe who may, and who may not, be eligible to be drawn as jurors; but it may also question each person drawn as a juror, as to his sentiments in regard to the particular law involved in each trial, before suffering him to be sworn on the panel; and exclude him if he be found unfavorable to the maintenance of such a law."* [footnote]

[footnote]
*To show that this supposition is not an extravagant one, it may be mentioned that courts have repeatedly questioned jurors to ascertain whether they were prejudiced against the government- that is, whether they were in favor of, or opposed to, such laws of the government as were to be put in issue in the then pending trial. This was done (in 1851) in the United States District Court for the District of Massachusetts, by Peleg Sprague, the United States district judge, in empanelling three several juries for the trials of Scott, Hayden, and Morris, charged with having aided in the rescue of a fugitive slave from the custody of the United States deputy marshal. This judge caused the following question to be propounded to all the jurors separately; and those who answered unfavorably for the purposes of the government, were excluded from the panel.
“Do you hold any opinions upon the subject of the Fugitive Slave Law, so called, which will induce you to refuse to convict a person indicted under it, if the facts set forth in the Indictment, and constituting the offence, are proved against him, and the court direct you that the law is constitutional"
The reason of this question was, that “the Fugitive Slave Law, so called,” was so obnoxious to a large portion of the people, as to render a conviction under it hopeless, if the jurors were taken indiscriminately from among the people.
A similar question was soon afterwards propounded to the persons drawn as jurors in the United States Circuit Court for the District of Massachusetts, by Benjamin R. Curtis, one of the Justices of the Supreme Court of the United States, in empanelling a jury for the trial of the aforesaid Morris on the charge before mentioned; and those who did not answer the question favorably for the government were again excluded from the panel.
It has also been an habitual practice with the Supreme Court of Massachusetts, in empanelling juries for the trial of capital offences, to inquire of the persons drawn as jurors whether they had any conscientious scruples against finding verdicts of guilty in such cases; that is, whether they had any conscientious scruples against sustaining the law prescribing death as the punishment of the crime to be tried; and to exclude from the panel all who answered in the affirmative.
The only principle upon which these questions are asked, is this - that no man shall be allowed to serve as juror, unless he be ready to enforce any enactment of the government, however cruel or tyrannical it may be.
What is such a jury good for, as a protection against the tyranny of the government? A jury like that is palpably nothing but a mere tool of oppression in the hands of the government. A trial by such a jury is really a trial by the government itself - and not a trial by the country - because it is a trial only the men specially selected by the government for their readiness to enforce its own tyrannical measures.
It that be the true principle of the trial by jury, the trial utterly worthless as a security to liberty. The Czar might, with perfect safety to his authority, introduce the trial by jury into Russia, if he could but be permitted to select his jurors from those who were ready to maintain his laws, without regard to their injustice.
This example is sufficient to show that the very pith of the trial by jury, as a safeguard to liberty, consists in the jurors being taken indiscriminately from the whole people, and in their right to hold invalid all laws which they think unjust."