You Should Know

arnt red states also using undocumented and prisoners as part of the census in thier states too,.

In the US our census counts residents, not citizens. While undocumented immigrants are historically under counted, this still seems to be based on the assumption that most countries don't include undocumented immigrants in population counts which is a flawed assumption.

Please provide some source that shows this is more than a shower thought.

This does depend on the methodology stated by the institution collating the data. The most recent methodological statement I can find from the FBI's stats reporting indicates it uses locality population estimates derived from the federal census - which in turn aim to count not the people each locality has registered as a resident, but the number of people who usually live and sleep in a locality regardless of documentation status.
Obviously, undocumented migrants may consciously attempt to be undercounted in that divisor but they don't necessarily disappear entirely.

The other angle on this I've seen multiple times is comparisons of crime rate per capita for populations segmented by migrant status like this, where the usual conclusion is "A person is less likely to commit crime, given that they are a migrant". It seems pretty believable to me that this reflects a raised background level of caution around crime caused by migrant status.

Um Ackshually, there are many places where even "undocumented" people can be considered "registered" in this sense. "Undocumented" simply means lacking the authorization to be (and work) in the country, and is really just a minor paperwork violation unless an actual crime is committed in rhe process.

So, many localities will try and integrate these people into the community, and provide them the same local services everyone else gets, by simply not asking them to show their passport first. So, they might be able to get their name on utility bills, and use that as proof of residency to get a drivers' license, in spite of their lack of status. (This notion that undocumented people still deserve human dignity really irks Conservatives, even though they all had ancestors who held the same status here at some point.)

This is really at the heart of what a "sanctuary city" policy is all about. It's a recognition that a local government has a responsibility to all people living in it, regardless of their immigration status. And that local officials really don't have the tools to be able to determine that anyway, so a local official won't care about someone's immigration status unless they are on the wrong side if the law. (Which also exposes the lie that these cities are less safe. If anything, sanctuary policies make it easier to kick out the miscreants, because no one is spending time chasing down undocumented people who are not causing trouble, leaving more time to find the bad eggs)

Counter point, Superman. Illegal immigrant, made the crime rate drop overall by making it unsafe to be a criminal.

/j

Using your logic, I could drive to the next town over commit some crimes and have the same effect. Pinning it to undocumented people is a way of trying to frame the discussion in a xenophic way.

Its a fair point, and well explained. However, I think it implies that illegal immigrants are fine so long as they're not more criminal than the general population.

Generally if somebody is using crime statistics to argue for more immigration control, they're probably the kind of person that believes the only acceptable amount of crime for an illegal immigrant to commit is zero crime.

I wouldn't call this so much a statistical error but a human one. While the exact number may be unknown, somebody with a pencil sat down somewhere and counted some beans on a sample, which a math whiz can extrapolate to get to a total population number that's closer to the truth.

Never trust a statistic, which you haven't forged yourself.