The fate of the Senate's health care bill might rest on a debate that hardly anyone seems to fully understand. It's all centered on a provision Sen. Ted Cruz added to the bill, which would let insurance companies sell plans that don't comply with the Affordable Care Act's insurance rules, as long as they also sell plans that do meet those requirements.
Cruz's amendment requires insurance companies to pool both sets of plans together when setting the premiums for each one. But that could be a deal-breaker for Sen. Mike Lee — he's not sure he can support the bill unless this single risk pool is broken up. Policy experts, meanwhile, aren't sure whether that would make much of a difference, or how all this would even work.
Why this matters: This is why complicated healthy policy ideas are generally publicly scrutinized for weeks — if not months — before they have a shot at becoming law. If the GOP health bill passes the Senate next week, there's a good chance no one will fully understand its effects until they begin to happen.