I think the convention will be pretty peaceful
The moving parts of the Obama marriage announcement interest me. I was genuinely surprised and thus find it all intriguing.
It is my hypothesis that there have been a lot of off-the-record discussions between campaign and/or WH staff with movers and shakers in some of the big rights organizations essentially promising Obama's endorsement of marriage equality in exchange for a peaceful Democratic convention.
If the announcement and its timing lead to a more peaceful convention and a more united party I am all for it.
Sources of potential convention discord:
1) Once amendment-hate passed in North Carolina it was inevitable that there would be a base effort to protest the convention venue in NC, which would be nasty.
2) The Democratic Party Platform was going to include marriage equality no matter what, and it would be best if the President was supportive of the platform. And any effort to fight it or scale it back would have been nasty.
Some reasons for thinking this was widely discussed, at least hypothetically, in the way such things are discussed. "If Obama came out for marriage equality would that make your members less locked into protesting the convention venue?"
1) Obama has said that he was going to endorse marriage equality "some time before the convention" and that Biden's loose lips merely sped up the process. But since he made his comments a day and a half after the NC hate-amendment passed I don't think Biden's loose lips were really the precipitating factor. If he was going to do it "before the convention" then it made good sense to do it timed to deflate a move-the-convention movement.
2) Obama also said that "this was in the works for some time," which suggests actions and plans, not merely personal reflection.
3) Politico had notable folks' comments on the ABC breaking news up really fast, like 30 minutes, and Michael Yaki, a member of the U.S. Commission on Civil Rights, had this oddly nuts-and-bolts first-blush reaction:
The fact is, with the DNC convention occurring in North Carolina, he had to defuse a potentially volatile situation involving the site selection (Charlotte, even though Charlotte as a whole voted against Amendment 1) and the platform. As the National Platform Chair in 2008, we worked to finesse then-candidate Obama's position by using the code word "families" for same-sex couples, which has legal importance as far-reaching as the word marriage, but less politically loaded. Now, four years later, the party and the president can move united toward the convention without distraction and keep the attention and attacks squarely focused on Romney.