1. Lots of businesses would fail, and we would experience another great depression. 2. You don't like populism now? The risks of outright fascism (beyond what you could say we already are experiencing) would go up exponentially.
The main problem with the Ron Paul acolytes is they think that society wouldn't have a massive breakdown in the face of an extremely deep depression - it would just be "the smart entrepreneurs would buy up the assets and build something better!" - but they never talk about how they would deal with the breakdown in democracy and basic government systems that would be a likely result.