I'm not sure if that's completely true. Price development has a large psychological component as well, so even if you take away the cause the prices may continue to rise simply because people fear they will. Ironically this means the Tea Party will only make things worse with their fearmongering.
Well, this gets into your beliefs on monetary theory. In the long run, there can't be inflation that deviates from the money supply. And in the long run the government's control of the money supply is essentially absolute. Hyperinflation in the modern sense happens when the government is deliberately driving it for one reason or another. Whether they're just incompetent, or thought they were resolving some other issue and so it was justified.
MV=PQ
Velocity is the wildcard. That's the part that the government has no control over. But while V can collapse below trend and stay there a long time, and while it can fluctuate wildly in times of instability, it can't really do dramatic increases that are beyond the government's ability to compensate for. The trend of V is to increase at a slow rate over time as changes in technology and markets allows it to. It is not, as people who have an over simplified view of money believe, a constant.
Now nominal prices have, as you say, a momentum of their own. And inflationary expectations drive what individual market participants expect, and so build in to what price changes they make. So in the short run (in my view, not in a hardcore monetary theorist's view) the real economy drives prices. But the longer the view you take, the more that Money has to expand to accommodate changes in Price (and Quantity and Velocity, but that's a deeper story).
So inflation can happen, but only up to a point. But hyperinflation can't except with the cooperation of the government. While it can be extremely painful to put a stop to it, they can at any time put a stop to it.
There's also a problem of what people think of when they here or use the term hyperinflation. The US did not have hyperinflation in the 70s, as some people claim. It was high, but it was never more than double digit. Painful for some, quite beneficial for many.
There simply is no prospect of hyperinflation in America's future. Inflation, certainly. And there's an argument for more than we would be comfortable seeing, as our primary problem is debt (private even more than public). Claiming that hyperinflation is coming is either ignorance or demagoguery. It just has no real basis.