Why are you so sure about it being a verb?
Just kidding you, I know you meant it as the verb "scam" to fool someone else, but here it means a noun (a trick, a fraud scheme, sham investment, etc).http://www.thesaurus.com/browse/scam
The same confusion arises, for example, with words like "cheat".
One way to crack that enigma is by stablishing who or the thing it (the word) refers to. If it´s a person then we will know that it´s a verb, if a thing or abstract concept/word or a noun, etc then it´s a noun.
the Second Amendment is not some fraudulent circus scam designed to deceive, corrupt, and impoverish.
Here we know that "scam" is not about someone scamming someone else, but it´s more of a concept of "engano" (uma espécie de "espetáculo enganoso e fraudulento/falso.)