I'm late to the game here. Many good points have been made already.
First, let's not confuse racial / ethnic discrimination with IMG selection issues. It's clearly against the law for me to treat two US grads, or two otherwise identical IMG's for that matter, differently based upon their race, national origin, etc. However, it's perfectly acceptable for me to select based upon what medical school you went to, or what clinical experience you have. If I decide, based upon my experience, that graduates of BMS (That's the "Best Medical School") are terrible, I am well within my rights to decide not to interview them, even if their USMLE scores are good. As mentioned above, I often have no idea how good an international medical school is, and hence the importance of US clinical experience.
Another issue not raised previously is about visas. Many IMG's choose to train on an H1b visa, which requires that there not be an equivalently competent US citizen available to do that job. There is no question that this burden is met in FM, IM and some other primary care fields. However, I would have a problem with any foreign citizen getting an H1b visa in Derm, Rads, Anesthesia, etc. There are plenty of qualified US citizens for those positions. Please note that anyone who does not need a visa -- those with green cards, etc -- would be immune to this argument. A discussion of whether the US should offer J visas (training physicians in this country to take that knowledge back to their own country to improve health care there) is a subject for another thread.
Last, a quick comment about exPCM's discussion of the future of IMG's in the US. I agree that as US schools expand, whether MD or DO, there will be a shift from the Carib to those new spots. Presumably, those people who "just missed the cut" and would be the "top" applicants to the Carib, will now get into the US schools. The overall MCAT/GPA of the US schools will go down, and the same for the Carib's. This new influx of US grads will start to saturate the residency market. However, most of this growth is in the DO system, and it remains unclear whether the allo residency programs will simply accept them or not. Regardless, as pressure mounts and the number of residency slots starts to equal the number of graduates, I expect IMG's will get pushed out, and I expect Congress will do so not by trying to regulate the match (which could fall afoul of the anti-discrimination laws), but rather by closing the H1b visa. Without that, the interest of IMG's coming to the US will decrease exponentially.
However, this does beg the question asked in the H1b application -- When is an IMG equivalent or actually superior to a lower performing US grad? It's a tough question. The USMLE's theoretically tell us who is competent to practice medicine and who is not. But it's obvious that this oversimplifies the situation. I mean, if you get a 182 you're competent but if you get a 181 you're not? That's obviously crazy. My experience tends to suggest that those US grads scoring above the 25th percentile on the USMLE tend to do fine, but those below the 25th percentile (when I take them) tend to struggle more in my program -- not all, but much more likely than those with better USMLE scores. So, as a PD, the tough question here is given a US grad with low but passing scores (and an equivalent performance in medical school -- i.e. the bottom 25% of their class) or an IMG with good scores and perhaps some US experience, which is more deserving / the best risk / will make the best doctor / etc.
