At the opening of his show last night, Glenn Beck started ranting about how the Mark Sanford case proved you just can't trust any politicians -- not one of them.

Then, later on the show, Beck invited wingnut Rep. Michelle Bachmann, R-Minn., to come on and talk about why you shouldn't fill out your Census forms -- essentially repeating what she had said earlier on Fox.

Namely, that the Census was an overly intrusive act by Big Brother to pry into Americans' private lives, etc. etc., as she waved a long, detailed survey she claimed she had an advance copy of. She again charged that Census data was used to round up Japanese Americans during World War II.

Beck, of course, ate it up, and urged his audience to join Bachmann in her crusade.

Except, of course, that everything Bachmann said was untrustworthy: wildly inaccurate, grossly distorted, and downright mendacious -- not to mention completely nutty.

Ali Frick at Think Progress has the details:

First, both women were shocked that the Census would ask for people’s telephone numbers. However, that information is not required by law, and is used only to contact recipients who have incomplete forms.

Second, Bachmann is confusing the 2010 Census and the American Community Survey (ACS), a long-form survey sent out to one in 40 households (0.0028 percent of the American public) each year. The Census, sent out once every ten years, asks only about one’s age, race, and the type of home one lives in. The ACS, started in 1996, collects more detailed data used to distribute more than $300 billion in federal funds to local communities.

Most importantly, the questions that Bachmann is so concerned about — questions she suggests might somehow lead to internment — are not new questions (not to mention they frequently overlap with information given to the IRS every year). Census questions on race have been asked since 1790; home language since 1890; rent since 1880; and income since 1940. The Census has asked what kind of heating fuel heats Americans’ homes since 1940.

Finally, it’s a federal crime for any Census worker to violate the confidentiality of the Census form, punishable by a federal prison sentence of up to five years, a fine of up to $250,000, or both.

Now, the claim that Census data was used in helping the government found up Japanese Americans during WWII had a grain of fact in it: Later research revealed that the Census data indeed was plied by government officials during the internment.

But Bachmann is also omitting crucial information:

-- The data raids were empowered by the 1942 War Powers Act's suspension of the Census' confidentiality clause, which clearly stipulates that such mining is illegal. It only occurred during World War II. The confidentiality clause was restored by Congress in 1947.

-- It is currently a federal offense to reveal any Census data about individual citizens.

Finally, we have to admit to some confusion here. According to Glenn Beck's frequent guest, Michelle Malkin, the internment of Japanese Americans was fully justified anyway, and this seems to be a bit of received wisdom out there on Planet Wingnuttia these days. So which is it?

Beck should have stuck with his initial position: Politicians are innately untrustworthy.

Especially wingnut politicians like Michelle Bachmann.