At DTN, Chris clarifies that Obama's proposal doesn't cap payments based on Adjusted Gross Income, but on Gross Income. Most of the articles I've seen weren't that specific.
This is going to be fascinating. There's a big difference. Sen. Chambliss and Sen. Johanns (former Sec of USDA) had a go-round on this early in the 2008 farm bill fight (if I recall correctly). Let the bloodletting begin--us geezers need the entertainment (think of Imperial Rome and the gladiators).
(See here for Sen. Johann's release, per Chris.)
[Updated] I'm not sure of the logic here. Seems to me the AGI figure is better than a gross figure so the only thing going with gross gets you is the appeal of hitting the big guy, or at least someone who sounds bigger. That's not a good basis for policy making.