The Second Amendment protects the natural right to keep and bear arms, the same type of arms that crooks and thugs might use against you, and the same type of arms that government agents might use against you
We also know that the first thing tyrants do when they come to power is to disarm the population. Sometimes tyrants are jackbooted thugs. Sometimes tyrants are the majority in an elected government
To the framers of the Constitution, an armed population is the best defense against tyranny
No, it limits the Federals powers. Nothing in the constitution deals with Natural or God Given rights. I suggest you read the constitution again without your preformed ideas about what you think it says.
You are correct that the constitution does not mention natural rights very much.
But it does mention them enough for us to know the founders believed they existed.
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Amendment IX
The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people.
Amendment X
The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.
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So then clearly there is the stated assumption that the people, all individuals, to have inherent rights.
And combined with the Declaration of Independence, then clearly it is those inherent individual, natural rights, that are the only source of any authority at all.
And some natural rights are enumerated.
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Amendment I
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; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
Amendment IV
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
...}