Whether you agree or not they're constitutional.
The government is explicitly authorized - and encouraged - to have a militia requirement. This is a prime example of one, and far closer to the traditions of the Founders than not having such a law.
I note, also, that this particular law (according to news reports when it was passed) explicitly allows conscientious objection. If you find guns morally abhorrent, you are not required to arm yourself.
Now if you believe in anarchy you're being consistent. From an anarchist perspective a government shouldn't be able to mandate arming yourself because it shouldn't be able to mandate anything.
After about 46 years of political activism, though, I've decided I'm willing to settle for constitutional minarchy. So I don't have a problem with it - especially since it's primarily an authorization and recommendation, rather than an actual requirement with enforcement teeth.
I usually oppose passing laws to "send a message". (That's what resolutions are for.) But it CAN be done right. B-)
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"Obama’s Economists: ‘Stimulus’ Has Cost $278,000 per Job."
That means: For each job "created or saved" about five were destroyed.