I think it is ridiculous to insinuate that the American people cannot get competent care in the ED by anyone other than a EM residency trained physician.
ABEM or not, people have received competent care in the EDs for years before the 'specialty' even existed. Most oldtime ER docs are actually either FPs or IM docs who just went to work in the ED and never left. And other oldtimers did an internship somewhere, and just went to work in the ERs. Eventually they were either grandfathered in or took exams to get the same qualifications as new residency-trained ER docs.
Not to mention the non-physician providers out there in smaller towns; RNPs and PAs. And many a competent physician from every specialty has moonlit on his or her own license. In fact, I have been told by EM attendings themselves that "I really only triage people, but I don't like to think of it that way.." and "EM is really FP in a hurry."
Sorry, I do not agree with the implications that only ED trained docs should practice EM. Studies or not, I think it is simply a turf war. If you are ED residency trained; you probably will demand more pay for what you do. And if some intern trained only MD or FP doc walks in the door willing to work ED for $65 per hour, I can understand why you'd be p/o!