Still think this isn't a calculated political gamble? More from NBC's First Read:

Obama announces support for same-sex marriage, but walks a careful line to respect states’ rights and religious views – always with an eye on the middle. … Obama was going to do this, but Biden expedited this… And, of course, the politics – in short, this ain’t 2004. Gay marriage isn’t the divisive issue it was eight years ago, but there’s always risk in overreach. … It was another day not talking about the economy, which can be seen as both pro and con for Obama … and GOP caught a break because stories about whether there’s room for centrists were overshadowed and were not driving the conversation as they would have.