The problem with insurance across state lines is that insurance companies would create a policy in a state with lax regulation and rules and sell that policy everywhere else. It's the same sort of crap that allows credit card companies to set up in South Dakota because that state has lax laws over usury rates.
That's exactly what's meant by insurance not being able to be sold across state lines.
The issue isn't whether Kaiser can sell a Californian a Californian health plan and a Texan a Texan health plan, Kaiser can already do that. The issue is whether Kaiser is allowed to sell a Californian a Texan health plan.
I agree. And that's exactly the status quo for insurance in the US: every policy is subject to the regulatory requirements of the state in which it's sold. "Allowing" policies to be sold across state lines - which, as others have pointed out, is equivalent to preventing states from regulating policies sold within their borders - would reverse this.
