@csgordon@zirk.us @gwaldby

Yes, the executive shall execute the law. But laws are only legal if they are constitutional. Any unconstitutional law is one that the executive is not bound to execute.

So when Congress authorizes spending, effectively giving the president the option of spending, the president shall execute that by spending no more than Congress has authorized.

But if Congress orders the president to spend money, well that's just unconstitutional so the president is free to ignore that order. It's an illegal order, and unconstitutional order, so the shall does not apply.

This comes up most clearly when Congress authorizes the president to spend more than there is in the Treasury. There's no contradiction so long as we keep in mind that Congress does not spend money.