This seems to be a polite and intelligent stopping power discussion disguised as a thread about the 32 Long!
As far as stopping power goes, a lot of people have made a LOT of really good points so far. Not much in the way of bad information or mis-information that I can see. That's impressive for a stopping power thread that's made it to four pages!
I've been a Dpty Coroner now for 11 years, and have seen my fair share of shootings. The majority are self-inflicted, but a significant number have not been. I've also attended the autopsies and had the benefit of our lead forensic pathologist being a gun-guy, resulting in a lot of educational discussions and deeper investigation into the GSWs we had on the morgue table than is probably given by the usual pathologist.
That all said, I can tell you a few principles that I've learned:
1) It's the rare person who has anywhere near enough experience with real shootings to have this all figured out. I sure don't, and I suggest you regard with a strong dose of skepticism and suspicion anyone who does.
(That said, my opinion of Dr. Fackler is that he WAS on the right track. When he started, he identified three principles about stopping power: 1-shot placement - hits to CNS = instant incapacitation, hits to heart/aorta/vena cava/carotid = near-instant incapacitation, hits anywhere else equals whatever time it takes for that wound to bleed; 2-psychological factors - he cited an incident from the old west where a person was hit in the leg with a survivable wound but died soon thereafter due to believing he would die as well as several other incidents where people did not give up, even though they had devastating wounds and lived; 3-Bleed-out - based on the third aspect of the shot-placement issue, he started measuring bullets' permanent wound channels and penetration distances. Because shot placement is beyond his control [in the control of the shooter] and psychological effects were beyond his control [in the control of the shootee] or quantification [because no one can quantify it], he focused only on what he could quantify, which is wound ballistics. In turn this has become so overblown that the other two principles have been lost out of sight, and all anyone talks about is wound cavity... I still respect his work and his opinions, but their not the be-all, end-all "gospel" of stopping power.)
2) Because of all the unknowns, I don't believe 100% in any of the current standards of measuring stopping power. Permanent Wound Channel, Energy transfer, etc., all have some basis in fact and are measurable, but witness enough shootings, and it won't take long to learn that these "principles" don't apply almost as much as they seem to apply. Not very good statistical proof, is it?
3) Due to all of these experiences, I fall into agreement with most tactical (real life law enforcement, not tacticool) trainers I've worked with in law-enforcement: shoot as big a caliber as you can carry and shoot well, watch the front site and keep it on the center of mass (because bad hits are always better than fast/unaimed misses), keep shooting until the threat is gone. These do not solve every problem, but they come as close as we can with a handgun, which leads to point number 4:
4) If I know I'm going into a fight, I use: at close range, a shotgun with medium-sized buckshot (#1); or at long-range, a rifle. Handguns need not apply. They are compromises we carry, because we can't always have a long-gun on us. (And, that leads me back to the "alleged" real point of this thread... )
As far as the 32 Long goes, there have been numerous posts already that make really good sense, including the mentality of getting shot back in those days (fear of being shot and dying a slow death from infection was more important than actual incapacitation value, at least in civilized nations), the purpose of marking "fleeing felons," and a few others. There are a few points I'd make that I haven't seen so far (but I read this long thread kind-of quickly, so apologies if I missed it):
A) People were smaller way back when. I remember my granpa and great uncles and aunts all being smaller than my dad and later generations. I've seen some good data correlating this to modern changes in health care and quality of food (inherently, storage, and preparation) which happened to occur around WWII. Smaller people means a smaller caliber is just as effective. 32s back in the 10s and 20s were probably ubiquitous for the same reason 38s were in the 50s and 60s in law enforcement work... (Note that 38s became more popular with the rise of organized crime during prohibition and the depression. That's when the firepower war started between LE and bad-guys. That transition from victorian era to gangster era is also why the early gangsters wore suits and tried real hard to look like businessmen -- they were still trying to fit into the waning victorian convictions, because "lying low" was smart then, just as today...)
B) My wife and I both have past relatives who were in law enforcement in that time period, and the mentality of law enforcement was different back then too. Nowadays people call us because the neighbor's dog is barking and annoying them. Back in the old days, people would go over and talk to the neighbor. (What a concept!!) Not to mention this was the Victorian era when societally people were much more concerned with behaving in a "civilized" manner. In that society and law enforcement atmosphere, police had a more laissez faire attitude and only got involved when really needed. Somebody was fighting down at the bar? Well, as long as it wasn't an ambush and the people weren't hurting others or each other too bad, it was hands off... Kind of like a referee at a hockey game; only stepping in when it was really needed. In that kind of atmosphere, police attitudes were not as equipment oriented or intervention oriented as things are today. Therefore, the need for a "cannon" wasn't seen as very necessary.
C) Most police agencies which carried 32s were Eastern-US, which also feeds into the point above, as the eastern US was seen as "civilized" and not needing the strong interventionism... In addition, one cannot discount the factor the powers-in-charge would think about their troops opening fire with large-caliber weapons in a city. Wouldn't want the officers shooting at a bad guy hitting two kids in the tennament across the way because that big ol' 45 bullet just keeps on plowing through... This is in contrast to a lot of the Western US, where it was the tail-end of the "wild west" and a lot of officers still carried 45 SAAs. (See Elmer Keith's "Hell, I was there" for a good description of a shoot-out in Montana in the late 1800s.)
D) In addition to a lot of the ballistics comments already made by others, I would pull you back to thinking about the effect of a soft-lead bullet. That was the JHP of the 1800s and early 1900s. Still would expand, even at slow velocities. This made the 32 Long from back then more like a 38 Short w/ hardcast bullets we might shoot today -- both would cut about the same path in a body... (But of course, the 38 Short was loaded with soft bullets back in those days, too...) So, there is some genuine stopping power benefits to the 32 there that go beyond what we might think considering most of shoot fairly hard WW boolits today (hard enough at least that they won't expand without HPs at the slow velocities of 800fps or less).
In conclusion, I think the 32 Long was a good cartridge for it's application (Eastern US, metropolitan police and self-defense work) and it's day (when people were smaller and attitudes were different - both as far as being civilized and the fear of being shot and dying a horribly slow death from infection). Today, so many of these factors are gone that it's not as good a choice. No doubt, the 32 Long can be compared and contrasted with any modern caliber, based on measurable/quantifiable data, however, the question then becomes how effective are these comparisons to correlate to real stopping power effectiveness? Unquestionably, I don't want to be shot, even by a 22 CB cap, but if I'm getting shot no matter what, I'd choose to be shot with the weakest cartridge possible...
In my opinion, I'd carry the biggest thing you can. If I was planning on going into a close-range fight, it would be a 12ga to 20ga medium to small buckshot load (velocity is not important, so "tactical buck" is OK), Long range fight, a rifle, probably something 6.5 to 30 caliber, though my preference would be an intermediate cartridge, like the 6.8SPC or 7.62x39. Carrying a handgun is, IMO, a compromise. It is carried because you can't take a shotgun or rifle to the Friday night football game... Therefore, it depends on what you can conceal. I carry a range of firearms from a 45ACP Glock 21 or 10mm Glock 20 down to a Ruger LCP in 380. Just my opinion again, but I can get a 9mm Glock 26 in the same space as I can a 32 revolver, so I'd choose the G26 over that 32, but that's just me. If you have extra-confidence with your 32 which gives you an advantage in hitting the target, than there's nothing wrong with that choice. Again, I'd carry very soft bullets, perhaps 1 in 25 tin to lead, in a design as heavy as possibly with still being able to get to 750fps, and with a flat point.
Whew! I gotta go lie down now...