But..
The most commonly repeated argument is that the founders lived in a completely different world than we live in and couldn't foresee the changes.
This bothers me on several levels.
Really, in a certain way, it bothers me for the same reason Dead Poets Society bothers me in its teaching of literature - that whatever it means to you is valid. I basically blame that movie for why most people my age think that Robert Frost meant the exact opposite of what he really meant when he talked about the road less taken.
With literature, a certain amount of ambiguity and interpretation can be fun; but, that shouldn't change the fact that the original author meant something and we should understand that.
In law, ambiguity isn't fun. That's why the founders were deliberate with their words. I mean, you can interpret the Second Amendment as assuring the right of the militia to bear arms and not the people - you'd have to still be reading at a second grade level; but, you can do it. You would also have to avoid reading anything that Madison or Jefferson wrote on the subject; but, that's the point of being anti-originalist, isn't it?
I get that it makes life easier to embrace perspectives that stink of postmodernism and "my truth" and "your truth" and having to believe that different perspectives have validity; but, it inevitably leads to a less free, less just, and less prosperous world. It's inevitable that this view would lead to a Supreme Court nominee not being able to define the words that she's using.
The reality is that playing fast and loose with interpretation of the law will lend itself to the courts having too much power. If we're not accounting for the original intent of the law when we make our decisions, why write the laws to begin with? Why write new laws? Why repeal any laws? We'll just be operating under the whims of the courts.
Finally, the founders did account for a possible lack of foresight - they included the ability to amend the Constitution which we've done seventeen times since the ratification of The Bill of Rights.