To jump into Peter and John’s discussion: One simple way for McCain to demonstrate the sincerity of his supposed “new thinking” on immigration is to sign on to all 15 of Sen. Jeff Sessions’ specific commitments on immigration. McCain could even insist that he thinks legalization will be necessary in the future, but that during his first term he would oppose any legalization proposal in Congress and would veto any that reached his desk. This would give him the leeway to make legalization an issue in a reelection race, so that the American people could “certify” whether they thought the borders were secure, rather than asking border governors, who have no way of knowing in any case. If he swore this, on the souls of his grandchildren, as it were, even I’d vote for him. But, as John has observed, McCain isn’t a particularly good liar, and he’s incapable of making such a categorical promise because he is a committed, principled multiculturalist — the central reason for his support for essentially unlimited immigration.