I don't recall any Tea Party types claiming that nationalization has caused GMs poor performance. I think a lot of people question the wisdom of the US government spending $50 billion for a company with a market value of about $500 million. If the intent was to cushion the blow of GM's collapse, that $50 billion could have provided a very generous transition/retraining allowance for every displaced auto worker.

The failure of a company is not a failure of capitalism. Capitalism is about accountability, not infallibility. That the (once) largest corporation in the world can be brought to its knees if it forgets about its customers is a good thing. The concern about nationalized companies is that they may be exempt from this kind of discipline.