The federal government spends more than $50 billion annually on grants and contracts to colleges and universities, including research funding, student financial aid programs, and agency-specific grants. The Supreme Court has long held that Congress can attach conditions to federal spending under the Spending Clause (Article I, Section 8), but those conditions must be unambiguous, related to the federal interest in the spending program, and not coercive to the point of leaving states "no real choice." Presidents have increasingly used the threat of withdrawal of federal funding to compel institutional behavior beyond what statutes explicitly require. Courts have blocked some of these threats, finding that executive orders cannot impose new conditions on federal grants without congressional authorization.