Voters like Social Security as it is, and don’t want it cut. It’s remarkable, then, that most of the Republicans who would be president seem to be lining up for another round of punishment. In particular, they’ve been declaring that the retirement age — which has already been pushed up from 65 to 66, and is scheduled to rise to 67 — should go up even further. What the new attack on Social Security tells us is that the rules have changed. Nowadays, at least on the Republican side, the invisible primary has been reduced to a stark competition for the affections and, of course, the money of a few dozen plutocrats.