Why cite the founding fathers?
If you follow American political or social discussion, you have probably seen someone bring up the founding fathers and what they thought or would have thought about an issue. Most readers here have probably seen the "USA was founded as a Christian nation" - "No, it wasn't" arguments.
Whether or not an issue was touched upon by the founding fathers, I can't understand why it matters what they thought. What I mean is: why would anyone consider it an argument to cite the founding fathers? Their opinions, no matter how enlightened, don't bind modern day Americans. Modern Americans are completely free to break with the founders, as they have on several matters, including slavery, gender equality, etc.
Moreover, I don't see British newspaper columnists referring to King Henry the 1st or Queen Victoria, or Swedes referring to Gustav 1st Vasa when they want support for their views. Nor in more recently founded democracies without monarchs do you see references to old and long dead founders: Finns don't cite Snellman or Ståhlberg to support a modern political argument.
Is referring to the founders of a nation (that are no longer alive) an American phenomenon, and if so then why? Why do the founding fathers matter?