I believe the Founders realized the downfall of a pure democracy is allowing voters to elect politicians that promise benefits from the public treasury. The safeguard against this was allowing only property owners and heads of households to vote. Of course, this long ago went by the wayside, but nothing short of restricting voting rights to taxpayers will stop the runaway spending, because voters with no skin in the game always find it easy to spend other people's money.
A Republic demands equality under the law, respects the property rights of the individual and derives its just powers from those who work to support it. A Democracy demands equal suffrage under the government, expects the distribution of wealth and is destroyed by those who contribute nothing. Our Founders rebelled at “taxation without representation,” but neither did they desire representation without taxation. The voter ID America needs is a paid tax receipt.