I already answered this question for you on another thread.
In the Gitlow case, which "incorporated" the First Amendment, the court incorrectly applied "Congress shall make no law", by finding that it was allowable for a state to outlaw speech which might incite people to overthrow the government.
Without the militia clause, the Supreme Court could make the same assertion; that our Founders never intended to allow people to have arms which might enable them to overthrow the government. But that, in fact, is exactly what our Founders intended. It was exactly what was needed on April 18, 1775 and it is equally necessary today.
No, if that was exactly what they intended they would have said, "A well regulated Militia, being necessary to overthrow a tyrannical federal government, the right of the people to keep and bear Arms, shall not be infringed."
"Security of a free state" could mean anything -- secession, invasion by another state, invasion by a foreign country, insurrections, riots, or a tyrannical federal government
"Without the militia clause, the Supreme Court could make the same assertion; that our Founders never intended to allow people to have arms which might enable them to overthrow the government."
Oh baloney. You makin' this stuff up?
State constitutions galore omit the militia phrase and you don't see the State Legislature and the State Supreme Courts in a tizzy about the possibility of being overthrown, do you?