Looking at that would be a great way to create some really perverse incentives. "Let's spend more money on the armed forces and post office, to make the portio

Looking at that would be a great way to create some really perverse incentives. "Let's spend more money on the armed forces and post office, to make the portion that comes under Clause 3 appear smaller." A lawyer I spoke to told me that there's a question regarding federal law on the bar exam every single year, asking "From where is the power to create X law derived in the Constitution?" It's a different law every year, but the answer is always the same: "The commerce clause."