Here's that frame:
WASHINGTON — Sixteen years ago, the Democratic Party refused to allow Robert P. Casey Sr., then the governor of Pennsylvania, to speak at its national convention because his anti-abortion views, stemming from his Roman Catholic faith, clashed with the party’s platform and powerful constituencies. Many Catholics, once a reliable Democratic voting bloc, never forgot what they considered a slight.
This year, the party is considering giving a speaking slot at the convention to Mr. Casey’s son, Senator Bob Casey of Pennsylvania, who like his late father is a Roman Catholic who opposes abortion rights.
William A. Galston, a domestic policy adviser to President Bill Clinton and now a senior fellow at the Brookings Institution, said Catholics were the quintessential swing voters.
... Mr. Obama should also invite Mr. Casey to speak at the convention, he said.
“I spend a lot of time with Catholic intellectuals, and no matter how liberal they are and inclined to support Democrats, they speak with vehemence about the exclusion of Casey’s father from the 1992 convention,” Mr. Galston said. “They don’t accept any of the explanations. I think it would be a dramatic act of historical rectification that would resonate with Catholics.”