President Obama just gave $500 million of Your Money to the UN Green Fund

Democracy is a [theoretical] form of government

…which is not practised anywhere in the world, not even in the US of A.

No they discussed the differences between a Republic and a Monarchy, as well as the form that the government should take.

Actually, there exists a legal distinction in this, as it was defined at the time of the constitution. A constitutional ‘republican’ form of government had the following principles underlaying it, (as per the arguments in the federalist, and antifederalist papers, letters between parties to the constitutional convention, and the congressional archive and supreme court cases surrounding it).
1: Power must be separated into three parts, the executive (enforcing the law) the judicial (judging what the law is) and the legislative (codifying the law within the limitations of the constituting authority of that body).
2: Law must be general in its applicability. It cannot pick and choose those upon whom it is to operate, and must operate without codicils, exceptions, or grants of privilege. (Federalist 57, article 1, sections 9 and 10 on attainder).
3: Law must not be ambiguous, or arbitrary.
4: Any legislation passed that is outside of that delegated authority is no law at all, and had no legal authority from the beginning, as it was place as a fraud without authority, and all acts, comissions, omissions, and offices created by such a law are void not merely from the time finding it, but from its inception. The finding is merely a recognition that the law never could have lawfully existed.
5: No law can be placed that would accomplish anything that the constituting authorities cannot lawfully do individually.
6: The delegated authorities cannot be redelegated to a third party by that office created by the original delegation.
7: Offices created by the delegation of authority are limited by the constituting principles as well. No officer of the state can do things the state is forbidden, including in the enforcement of contracts, unlawful acts being impossible as either forbearances or considerations in contract.
8: That there must be systems of recourse for violations of those forbearances created within that constitution, both in the legal and physical realm.
Sovereignty, as a subject, is sorely misunderstood. Unlimited sovereignty would be the power to do anything one wants, as they are the creators of law… but sovereignty comes at a price. One must respect the rights, and properties of other sovereigns, or one becomes something quite different, an aggressor and outlaw.
While sovereignty in the United States is delegated to the system of states and federal government, it is retained by those who created them, and by whom and for whom all power exists and acts, and engaged with the limits of that original sovereign power to not be able to diminish that of others. It is retained by the people, who created the states, and for whom the constitution was created, the state governments being unable to place in the hands of another that which was borrowed, in the same principle that no operator of a store may legally sell or destroy it, without the express, written permission of the title holder.
Note that this argument does not come from a vacuum.
Reid v. Covert, 354 US 1 (1957) discusses the limits of constitutional treaty power.
Yick Wo v. Hopkins(118 US 356, 1886) discusses sovereignty at pages 369-370. This is building on a large body of previous cases, in light of the 14th amendment, and arbitrary application of the law.
Cummings v. Missouri (71 US 277, 1867) discusses bills of attainder, and its sister case, Ex Parte Garland, discusses their application via a state constitution as being impossible under state authority.
The federalist papers (under federalist 44, and 57) discussed attainder, and made a federal guarantee that congress could pass no law that did not equally affect itself, its friends, and the whole of society, that being the most certain way to safeguard rights of individuals and groups from governmental interference. The only exemption was the regulation (or making regular) of the militia and army (as seen in the Militia act of 1792).
The privileges and immunites under article 4 were discussed under Dred Scott v. Sandford (60 US 393, 1857) at pages 416 and 417 and the much earlier Prudence Crandall cases, being established that they were nationwide, belonged to all citizens… and that those who owned slaves, and the states, wanted to deprive them to maintain their monopoly over slaves. They were well defined, and the language in this document defined the language of the 1866 civil rights act, and the 14th amendment. These privileges and immunities were the separation between being a slave and a free man in the US. They are the legal authority of sovereignty under the British system, as the crown was the only ‘person’ (as distinct under the human wearing it) who could own land, allow businesses, or be allowed to maintain the power to defend itself. The citizens of the United States were guaranteed this form of government to safeguard these rights, which would be meaningless under a pure democracy.
And the people could not delegate a power they did not possess. They cannot delegate the power to diminish the rights of others (though the states claim that power even today, so long after the 1871 civil rights act and the 14th amendment allowing punishment of those deprivations, currently under title 18, section 242 USC.
They cannot collectively vote away the property, liberty, or lives of any minority, no matter how small, nor establish any religion, nor mandate any religious observance. They cannot interfere with peaceable assembly, nor interfere with the public discourse, no matter how objectionable the state finds it.
That is the difference between a ‘republican’ form of government and a pure democracy. In the republican form of government, that constituting authority, the people, are equally bound against transgressing the rights of others. In a pure democracy, nothing prevents changing or altering any aspect of government, up to and including depriving others of a voice in government, depriving others of their voice in the public sphere, or depriving people of their right to defend themselves, their property, and their livelihoods.
And that’s why there is such a strong movement to move over to pure democracy, it fits the agenda of those who would like absolute power.
As was said in the federalist 10, by Madison himself:
“From this view of the subject it may be concluded that a pure democracy, by which I mean a society consisting of a small number of citizens, who assemble and administer the government in person, can admit of no cure for the mischiefs of faction. A common passion or interest will, in almost every case, be felt by a majority of the whole; a communication and concert result from the form of government itself; and there is nothing to check the inducements to sacrifice the weaker party or an obnoxious individual. Hence it is that such democracies have ever been spectacles of turbulence and contention; have ever been found incompatible with personal security or the rights of property; and have in general been as short in their lives as they have been violent in their deaths. Theoretic politicians, who have patronized this species of government, have erroneously supposed that by reducing mankind to a perfect equality in their political rights, they would, at the same time, be perfectly equalized and assimilated in their possessions, their opinions, and their passions.”
And my apologies for the long post. It’s a complex subject.