I'm sure there will be more on this over the next 24 hours, but this would definitely be a game changer in the US. I think that they must know that if they do it now, it would have almost no impact on the mid-terms and could regain them support among the younger and swing voters.Proposition 8 opponents believe the president signaled his intention to file a brief when he declared in last month’s inaugural address that gays and lesbians must be “treated like anyone else under the law.” An administration official said Obama was not foreshadowing any legal action, though the administration was considering filing a brief.
It certainly would be a principled stand for a President to take.
Since both the legislature and the judicial branches of federal government are involved in an issue that many will argue is States' Rights, I see no reason for the Executive Branch not to weigh in as well.
Let the howling from the right wing commence.