As interpreter of the Constitution it is his responsibility to do such things; but it is odd and not the least bit hypocritical that conservatives now read an implied right (to self-defense) in one part of the Constitution but not other implied rights (such as medical privacy) when arguing against something like abortion.

Original intent means a lot of things to a lot of people. As you correctly address, there is no original intent of the founders, as numerous men made numerous decisions across that fateful summer. They hardly developed a clear, unifying theme that could be called their original intent. When someone cites a political position or constitutional interpretation as original intent, they are most likely refering to an “original majority opinion at one moment in time.” I am entertained when someone cites an opinion as original intent because I imagine all sorts of other fun “original intent” arguments (many of which were actually voted on). For example, my man Gouverneur Morris proposed that one legislative house represent the land-owning interests of the country. His original intent was to give the wealthy serious protection from the thieving congressmen of the middle-class and poor. Another convention badass, George Mason, didn’t sign the final document at all. His original intent was to bury the tyrannical federalist form of government (unless a bill of rights was added, which it eventually was). So, the original intent of the members was quite diverse.

There are many alternative ways of looking to the past discussions of the founders for future guidance. I think textualism and contextualism provide stronger methods for examination than original intent. John Yoo provides an excellent breakdown of original intent and contextualism regarding war powers in his book “The Powers of War and Peace: The Constitution and Foreign Affairs after 9/11.” Whatever you may think of him, he positively nails down his legal arguments.