ABC News has broadcast a preview of President Obama’s remarks from an interview with Robin Roberts today, and the President affirmed his support for marriage equality, saying that same-sex marriage should be legal. Here’s the full quote:

OBAMA: I have to tell you that over the course of several years as I have talked to friends and family and neighbors when I think about members of my own staff who are in incredibly committed monogamous relationships, same-sex relationships, who are raising kids together, when I think about those soldiers or airmen or marines or sailors who are out there fighting on my behalf and yet feel constrained, even now that Don’t Ask Don’t Tell is gone, because they are not able to commit themselves in a marriage, at a certain point I’ve just concluded that for me personally it is important for me to go ahead and affirm that I think same sex couples should be able to get married.

Before this, the President said that he previously endorsed civil unions because he “thought that would be enough” to give gay and lesbian couples the rights and benefits that go along with a loving relationship. But then there was this evolution, to use the parlance, in his thinking. Actually, it’s a circular evolution, since Obama wrote “I favor legalizing same-sex marriages” in a questionnaire for the state Senate in Illinois all the way back in 1996.

This concludes one part of a years-long struggle, where LGBT activists demand, and then achieve, support for equality, inch by inch. It’s very clear that this would not have happened without activists pushing at all levels. In addition, the well of LGBT fundraising support in this election cycle has been vital for the President, to the extent that it’s replaced much of the dropoff from Wall Street in 2008.

Joe Biden jumped the gun on this a week ago by pronouncing himself “comfortable” with marriage equality. This heightened the ridiculousness of the President’s attempt to play all sides of the issue, making it a question of character and principled belief, and forced this disclosure out into the open. There’s political calculation all over this, as there normally is with any Presidential decision. At the end of the day, however, the flip-flop went to the side of more justice and more rights. And ultimately, this will not have much impact, if any at all, on the Presidential election. If it did, Obama wouldn’t have done it, no matter how much controversy ensued.

ABC will broadcast the bulk of the interview on their news program tonight and on Good Morning America tomorrow.

More from David Corn. And here’s another interesting excerpt from the interview:

“This is something that, you know, we’ve talked about over the years and (Michelle Obama), you know, she feels the same way, she feels the same way that I do. And that is that, in the end the values that I care most deeply about and she cares most deeply about is how we treat other people and, you know, I, you know, we are both practicing Christians and obviously this position may be considered to put us at odds with the views of others but, you know, when we think about our faith, the thing at root that we think about is, not only Christ sacrificing himself on our behalf, but it’s also the Golden Rule, you know, treat others the way you would want to be treated. And I think that’s what we try to impart to our kids and that’s what motivates me as president and I figure the most consistent I can be in being true to those precepts, the better I’ll be as a as a dad and a husband and hopefully the better I’ll be as president.

More reactions over at Pam’s House Blend.

UPDATE: An important point from Richard Kim:

Obama, however, stopped short of lending full support to the multi-state legal and political campaign for marriage equality. According to ABC News, the President stressed that his is a “personal position,” and he continues to think that states should decide the issue independently.

In at least one crucial way then, Obama’s announcement stops short of a full reversal of policy. In the past, Obama has said that he thinks that “gay and lesbian couples deserve the same rights and legal protections that straight couples already enjoy,” but does not endorse same-sex marriage per se. This is not a coherent position. There simply is no legal category outside of marriage that grants same-sex couples all the rights and legal protections that straight couples enjoy—not civil unions, not domestic partnership arrangements. Only marriage recognized at the federal level and in all fifty states would do that.

The President has in the past opposed all discriminatory amendments to state Constitutions that would ban marriage equality. But he’s still taking a “state’s rights” position on the issue, regardless of his personal beliefs.