What is a banker?

I engage people of all stripes on Facebook, and I press them when they make political statements I don't like.  One source of sustained pressure for me of late has been Ron Paul's views on banking.  "Just read the website!" his faithful say, as though I don't know what Ron Paul might be saying.  I was a vice president at a commercial bank earlier in life, and I have been watching Ron Paul and people like him for years.  If you want to send America from slump to stone age, follow Ron Paul--that's my opinion.  But even before one gets to his or her own opinion on banking, they need to know what a banker exactly is.  People who think they have credible ideas on how banking should be nonetheless seem to fold when simply asked what a banker does.  How can this be? How can it be that people imagine they know that something is right for banking, when they don't even know what bankers do?