It certainly looks like the media is ONCE AGAIN causing conservatives to attack the wrong boogy man - this time BIG SPECULATOR.
Sure, you can get short-term run-ups by people speculating long, but supply and demand will ALWAYS win out in the end, and those run-ups will come down just as fast...as did happen in 2008.
In the end, the ONLY thing that matters is SUPPLY AND DEMAND and if there is enough supply, prices simply CANNOT stay high, no matter what BIG SPECULATOR, BIG OIL, or BIG GOVERNMENT wants (unless they tax it more). That simple.
Your theory fails to account for the fact that commodities are up across the board, across the globe. That cannot be explained by supply and demand alone, and especially in a weak economy - just as the runup in the price of silver in the early eighties was caused by the Hunt brother's speculation.