(a) They can't do that if you're a citizen; you have a right to enter regardless of whether you have a passport. Heck, there might not even be a place to return you to.
(b) That wouldn't be a "penalty" in the law regardless (and this has nothing to do with criminal vs. civil vs. "illegal" vs. whatever). That is, if you do prove your citizenship somehow, they cannot turn you back to penalize you for not having a passport—period.
The question is whether you can prove your identity (and thus citizenship) without a passport. There are lots of ways to do this, and it seems [1] that "A Certification of Report of Birth, issued to U.S. citizens who were born outside the U.S." is sufficient to prove citizenship in other cases, so it seems plausible that that's sufficient for entering the country too.
(I wouldn't be surprised if even a State ID would be sufficient for them to look up your citizenship info in practice, since they cannot deny you entry if they discover you're a citizen.)
[1] https://www.law.cornell.edu/cfr/text/42/435.407 (note that this section is NOT specifically for entering the US; I'm just providing it as an example of documents that adequately establish citizenship in other cases)
No, your link is about a totally different situation. We were talking about frequent refusal of entry at the border (which would be by CBP, btw) after evidence of citizenship other than a passport has already been provided, based on brown skin color. You're linking to a few dozen deportations over 6 years, which occur to existing residents after they're in the country (which is performed by ICE). And on top of that it's not clear what evidence of citizenship (if any) they had provided prior to the arrests, though it's already a different situation anyway.
I was verbally refused entry (as in explicitly they said I would not be let into the country) at the border while presenting a crisp, authentic US passport that CBP accepted as my genuine passport. I am white, US born citizen appearing as middle class and from middle america. There was absolutely no mistake about my documents proving my citizenship, and no doubt whatsoever I was a US citizen. I was tossed into a holding cell with all brown people whom I could barely communicate with.
The CBP operates with virtual impunity at the border. It is illegal to record them, unlike basically any other officer in execution of his/her official duties. When I contacted immigration lawyers, I learned basically none of them are interested in bringing a suit against CBP for abuses, as it's an incredible long shot mission and hassle.
After several hours of interrogation, and waiting for what I believe is an HSI detective (DHS, but not CBP) I was finally allowed into the country, with a warning "we can cancel your passport." (LOL, CBP officers cannot do that) Interestingly that HSI detective found the whole thing totally uninteresting and I was sent on my way almost as fast as he got there.
On yet another occasion, CBP tossed me again in the holding area full of brown people, stuck a dog on me THAT DID NOT ALERT, and then wrote in their report that <I slightly paraphrase> "a dog sniffed his asshole and alerted" after which I was strip-searched (intimately), cuffed, chained booked, tossed in an actual imprisonment cell and then loaded up in a prisoner transport van and dragged through hospitals (multiple of them, until they could find one with a corrupt enough doctor) for 16 hours while nurses and doctors in on their scam treated me like I was some drug trafficker. The Assistant United States Attorney was notified and she and her ilk piled on the fuckery, signing off on a fraudulent warrant authorizing my "internal examination." When their investigation came up with nothing, they dumped me back at the border, without any apology and presumably without removing me from their shit-list, which plagues me every time I enter the country.
If you are on a certain "shit-list" of CBP, they will fuck with you to no end, and there is very little you can do about it. The constitution is "suspended" at the border and half-suspended anywhere 100 miles adjacent. I tried to explain I still have some rights as a citizen, and the CBP Officer said "well I'm about to show you my rights" before strip-searching me. Seriously, what are you going to do? You can't record their actions, and what you can get through FOIA is minimal. Their agents lie on the reports, so whatever they write is worth about as much as a piece of toilet paper. When I tell these stories most people laugh, ask me what I must have been doing wrong, or say it's all in the course of securing the border. Sadly things are not likely to change, and in fact only seem to be getting worse.
Have US citizens been denied entry? I don't know, I just know as a normal looking and sounding white guy American I myself have had a CBP officer try to deny me entry, and I can't imagine what it would be like if you're a US citizen who only speaks spanish and looks hella indigenous. Maybe then you're lucky enough to get in, only to be finger raped [0] at the direction of CBP officers on a warrantless fishing expedition for a cavity search. If I were a betting man people who were denied entry probably did the same thing I did, which is contact a lawyer and find out you have basically no options, deal with your reality in whatever way you can and then move on with your life.
> I was verbally refused entry (as in explicitly they said I would not be let into the country)
> I was finally allowed into the country
With regards to the discussion here, note that you weren't actually denied entry, regardless of how the officer may have phrased it to you verbally. Your permission to enter was withheld for some time and you were given a (very) hard time (as I mentioned can happen in my initial comment), but eventually allowed to go through. If you were actually denied entry, you would've been (say) placed on the next flight back, or left at the airport to figure your way out, or something like that—not taken in for interrogation and eventually let in.
(Obviously what they did to you sounds horrible; I'm not questioning that here. I'm just clarifying that, for the sake of the original discussion and the OP, this this was not a denial of entry, and is of course also unrelated to lack a passport.)
True it was a long-run entry but short-run denial. Although I would call being refused entry for the express reason of denial, followed by a reversal of the decision as a denial + a delay + an acceptance in the country. A right delayed is a right denied and all that, especially if it was delayed for the express purpose of indefinite denial.
(a) They can't do that if you're a citizen; you have a right to enter regardless of whether you have a passport. Heck, there might not even be a place to return you to.
(b) That wouldn't be a "penalty" in the law regardless (and this has nothing to do with criminal vs. civil vs. "illegal" vs. whatever). That is, if you do prove your citizenship somehow, they cannot turn you back to penalize you for not having a passport—period.
The question is whether you can prove your identity (and thus citizenship) without a passport. There are lots of ways to do this, and it seems [1] that "A Certification of Report of Birth, issued to U.S. citizens who were born outside the U.S." is sufficient to prove citizenship in other cases, so it seems plausible that that's sufficient for entering the country too.
(I wouldn't be surprised if even a State ID would be sufficient for them to look up your citizenship info in practice, since they cannot deny you entry if they discover you're a citizen.)
[1] https://www.law.cornell.edu/cfr/text/42/435.407 (note that this section is NOT specifically for entering the US; I'm just providing it as an example of documents that adequately establish citizenship in other cases)