I beg to differ.
Krugman too sees the very existence of a political force so powerful to be beyond real regulation, potentially destructive to democratic government, or even just any adequate government. He DID write that he wanted the big financial players smaller, for that very reason.

His point is that doing it will not prevent financial crises and that he disagrees with people advocating only having smaller banks, without regulating them.

Earth provides enough to satisfy every man's need, but not every man's greed. Gandhi