All true, but how does it relate to the problems of the Great Recession? In previous downturns, like 1980-82 or 1991-92, interest rates were higher and inflation was a greater concern. The Fed says inflation is manageable. Republicans say it's such an incipient problem that the Fed needs to tear up its plans and keep it under control. But there just isn't any evidence that inflation is looming The primal fear of a weak dollar—something no politician claims to favor—is what's behind this Republican demand to fix a nonexistent problem.
The reaction to the GOP letter was angry. The reaction to Perry's comments was even angrier. From a political standpoint, this is probably good for Republicans, because they're on the record against a policy that can't do much to boost the economy, and that bet's worked well for them in the Obama era. It might be good for Democrats to understand how deep and existential, and radical, the GOP's critique of the Fed really is. For the Fed, it's a wash. Read the law. It can do whatever it wants.