Where Bachmann goes wrong is in her “solution”, if I can dignify it with that term. It’s not a good idea for a member of Congress to be urging people not to cooperate with the census.
And as a political matter it’s hard to imagine a more self-defeating strategy for conservatives. (“Yeah, we’ll just not get counted! That’ll show ‘em!”)
Nonetheless, I don’t think she was actually arguing that internment camps are just around the corner. I took her to be saying that there is a danger of census data being misused, with the camps being a spectacular example from history. Hence, her conclusion: “Americans were told that they wouldn’t have their information used against them … they did.”