A well-regulated Militia being necessary to the security of a free State, the right of the people to keep and bear Arms shall not be infringed. They are either ignorant of the subject or are choosing to ignore what the Historians and English experts say was the intent of the law. Everyone gets it. Somehow their interpretation changes when applied to guns.
Words change meaning over time.
An army composed of ordinary citizens rather than professional soldiers. A military force that is not part of a regular army and is subject to call for service in an emergency. The whole body of physically fit civilians eligible by law for military service. Of course more importantly the Second Amendment was never dependent on the militia because the militia meant all the people. To disarm the people is the best and most effectual way to enslave them.