When America's first draft was enacted during the Civil War, you could buy your way out of service for about $300. That was a lot of money back then but it did allow the wealthy a way to keep themselves and their kids out of uniform.

During subsequent drafts, you couldn't buy yourself out but there were various exemptions for religious views (e.g. Quakers), education deferrments, "wartime critical jobs", etc. It really wasn't that difficult for someone with connections to avoid service if he wanted to. In the meantime, the average kid from the block whose bones showed on a X-ray would probably end up being 1A.

I've opposed the draft for years in part because of these exemptions. I have no faith that Congress would enact a draft that would endanger their kids (and those of their contributors) to the same degree as ordinary people. Furthermore, I see the draft as a violation of the 13th Amendment's prohibition on involuntary servitude.