Just because something is “settled law” doesn’t mean everyone will follow it. The settle law thing is really a dumb argument. Plus, Laurence Tribe was an Obama campaign adviser in 2007 and 2008. He was helping to divert attention away from Obama.
It is not a matter of following it. Obama was never challenged by the GOP and the Tribe/Olson opinion was requested by the Senate to determine McCain’s eligibility. If it was settled law re the definition of natural born citizen, then why ask for a legal opinion?