As an epic civil rights trial kicks off today in San Francisco, the ultimate constitutionality of same-sex marriage is perhaps the least important decision Chief Judge Vaughn Walker will make. He won’t have the final say on that.

What will matter more are his decisions and actions along the way — the factual findings, evidentiary umpiring and the overall tone and tenor of the proceedings. He is sure to be second-guessed on all those fronts, too: One conservative commentator has already suggested Walker’s preference for cameras in the court will turn the federal challenge to Proposition 8 into a circus trial.