My wife is a current resident in the US and she graduated from a medical school in SE Asia. She spent tens of thousands of dollars on exams, observerships (yeah, one has to pay to observe at the hospitals and there are only a handful of them that accept observers; there are a few clinics that take money for observerships), unpaid volunteering, unpaid research, and travels. All of that to make her resume stronger so that she can have a better chance at *residency lottery*. Worse, the residency spots are sometimes decided by internal contacts/introductions--just like a regular job. If one's year of graduation is higher than 5, it becomes much harder to get a residency match. Every year, we are leaving behind some perfectly qualified medical doctor candidates in the convoluted, costly and unnecessarily-restrictive system.
No wonder doctors in the US expect to make way above what doctors in other developed countries make because of the artificially tough road they have to traverse to become professional doctors in the US. This, in turn, affects (increases) the health care cost that we have to pay when we go see doctors.
In summary, it should not be that difficult to become a general (internal medicine) doctor in the US. Actually, I'd go as far as to say that it should not be that difficult to become a doctor of any specialty except a handful like (neuro/orthopedic/opthalmic/cardiac/general) surgeons. A lot of other developed countries (or countries like India, which produces very capable medical doctors) do away with residency bullshit. There must be something that the US can do to make hopeful residents' lives easier.