Read this column by Dana Milbank in the paper today:
This matters, because it means the entire premise of the Arizona immigration law is a fallacy. Arizona officials say they've had to step in because federal officials aren't doing enough to stem increasing border violence. The scary claims of violence, in turn, explain why the American public supports the Arizona crackdown.
I know what he means, but I'm a stickler for such things, and it's wrong to call this a "fallacy." A fallacy is an error in reasoning and Milbank is simply alleging that the factual basis of the law (more on that in a second) is false. Were it to be true, then there would be no fallacy. So they're just mistaken about facts.
As for the allegedly false factual basis, the most Milbank can say is that some of the claims made by various supporters of the Arizona immigration law are false. I don't think that amounts to the claim that the "entire premise of the law" is false. I imagine there are other premises–such as illegal immigration is illegal, and so forth–that supporters of the law can point to.
None of this means, of course, that the law in question is a good idea–it's just not a fallacy.
I suppose one could treat the premise as a single-proposition argument, and then propose something like an ignoratio elenchi. But that would seem to redefine the notion of "strained."
If the Arizona legislature is basing their claims on an effort to "stem increasing border violence" there may be a straw man depending on whether or not such violence is increasing and is causally related to illegal immigrants from Mexico.
1. Illegal immigrants from Mexico are getting to the US through Arizona
2. If P1, then violence increases.
3. We pass law X.
P2 seems like a candidate for non sequitur, or maybe a false cause as the increase in violence, if it exists, may be due to/caused by vigilante groups. Also, this could be a simple appeal to fear by the legislature, insinuating that "If we don't step in, you'll be at risk of violence from Mexicans." The author's accusation of fallacy is muddled, but I'm not sure she's that far off.
Well, to put this another way, the "premise" wouldn't be a fallacy but rather false–as premises are true or false. Nonetheless, the article he (he's a he) writes makes it clear that he means the premise is "false" not "a fallacy."
Granted, or course, that premises aren't fallacious in themselves. If that's the point of the post, consider it taken. In charity, however, I was looking to correct I saw as the author's point-i.e. the argument, as he presents it, looks fallacious. What's a better way to point out the invalid move in the logical structure of the argument? (serious question)
In any case, I think the charitable version of the pro SB 1070 types is that they're just mistaken. I don't think there's anything necessarily wrong with their reasoning (even on your reconstruction). They may have misidentified the causes of the alleged problems they've been having, but that's just a factual problem.