Today the Prop 8 case is being argued before the Supreme Court, and a sweeping ruling that strikes the law down as unconstitutional could pave the way for full marriage equality being the law of the land across the country. Such a ruling would be a historic outcome for equality and civil rights in this country.

I grew up about a half a mile away from the birthplace of the gay rights movement — the site of the Stonewall uprising, in Greenwich Village — and throughout my childhood I had an up-close view of the ugliness of anti-gay bigotry. One thing that makes this civil rights battle different from others is that anti-gay prejudice and hostility haven’t been featured in popular culture and not many Americans have been exposed to them in the raw.

To appreciate just how far the movement has come, and how fast it has managed to force a massive cultural shift in favor of marriage equality and broad acceptance of gays, go read John Harwood’s remarkable piece tracing the whole story from Stonewall to the Supreme Court.

I spent my childhood on the far west side of Manhattan in the 1970s, at a time when it was little more than a gay ghetto. The open abuse of gays on the streets was a regular occurrence. The term “gay bashing” was in common use at the time. You sometimes saw young men from outside the city driving around and taunting gays with shouts of “faggot” for sport. I remember seeing young men creeping out the doors of underground gay clubs dotting the far west side early in the morning. As a kid I only dimly understood what they were hiding from and what they were looking for — refuge and acceptance — but now I understand that this period roughly corresponded with an era in which many gays remained in the closet. As Dem Rep. Barney Frank puts it: “We were all hiding.”

I remember seeing many of those underground clubs closed down after the AIDS crisis hit. Ronald Reagan’s longtime refusal to publicly acknowledge the AIDS epidemic was a regular topic of conversation. One of my mother’s best friends, a skilled mime who would regularly make the family crack up in laughter, died of AIDS far too young. AIDS ended up pushing gay rights into the mainstream, and Bill Clinton continued the process by aggressively spotlighting the disease and vowing to allow gays to serve openly (leading to Don’t Ask Don’t Tell), only to infuriate supporters by signing the Defense of Marriage Act amid a conservative backlash. Now DOMA is on the precipice of being struck down.

Just think: In 1972, gays were permitted to speak at the Democratic convention for the first time. Forty years later, gay marriage is in the party platform and it has been endorsed by an American president. The real credit here doesn’t go to public officials who belatedly acknowledged the inevitable, and ultimately were followers in the footsteps of a movement that helped compel an inexorable shift in public attitudes towards greater social tolerance. But it is nonetheless remarkable — and a testament to the power of that shift — to witness a president use his inaugural address for the first time to place the battle for gay rights in the context of the nation’s other great civil rights struggles, and explicitly claim that our quest for a perfect union won’t be complete until gays enjoy fully equal treatment before the law.

Incredibly, that goal — victory in a battle that first and foremost is about dignity, tolerance, and equality — is now a real possibility. Which is why people are massing outside the Supreme Court this morning, in hopes of catching a glimpse of civil rights history — of American history — in the making.

(Update: Post edited slightly for accuracy.)

* Will the GOP evolve on gay rights? A new CBS poll finds, as many others have, that support for gay marriage is at an all time high: 53 percent of Americans think it should be legal for same sex couples to marry, versus only 39 percent who do not. And this is stunning:

Thirty-three percent of Americans who now think same-sex couples should be allowed to legally marry say they once held the opposite view.

While solid majorities of Democrats (63 percent) and independents (56 percent) favor marriage equality, 56 Republicans remain opposed.

* Dems keep hitting Paul Ryan budget: The DCCC is out with a new Web video that pillories the Ryan budget for its deep cuts to retirement and other government programs that poor, middle class and elderly Americans rely upon, while quoting Ryan himself describing the budget as an expression of the GOP’s governing “philosophy.” Republicans plan to campaign on the Ryan plan by claiming it “balances the budget,” supposedly turning it into a positive. The Dems’ video suggests their answer will be to point to the unpopular policies and priorities that are actually in the Ryan plan.

* No end to the skittishness from red state Dems: I now have statements from all five red state Dem Senators who are being targeted by Mayor Michael Bloomberg’s ads. Only one — Joe Donnelly — is willing to say he supports expanding background checks, which is backed by nine in 10 Americans.

One has to hope they are withholding support temporarily to avoid being perceived as responding to ads from a New York Mayor. Let’s hope they are not allowing a policy decision that law enforcement groups believe could save many American lives to be dictated only by fear of the NRA.

* Brace yourself for some Scalia wisdom today: Adam Serwer has a dispiriting look at some of Scalia’s greatest hits from previous arguments over gay rights. Fortunately, all eyes are on someone else — Anthony Kennedy, who is widely seen as the key swing vote and has a history of good rulings in previous gay rights cases.

* What if Court upholds Prop 8 and DOMA? It is always possible that the court will deliver gay advocates a big loss, and in this sense, the Prop 8 challenge in particular has always been a major gamble. But as Josh Gerstein details, not only is this very unlikely, but even if it does happen, the dramatic swing in public opinion that has accompanied the legal activity of the last few years is itself a major victory and all but ensures eventual triumph.

* Court could rule narrowly in Prop 8 and DOMA: Robert Barnes has a good overview of all the legal options before the Court on both cases. But ultimately, this point may be the one that really matters:

A four-year legal battle to extend the right of marriage to same-sex couples no matter where they live gets its moment before the Supreme Court on Tuesday in historic oral arguments difficult to imagine even a decade ago.

* The ideal ruling for gay rights advocates: The New York Times aptly summarizes the best outcome:

In both cases, the court should rule that the Constitution prohibits the federal government and every state from defining the fundamental right of marriage so narrowly and fully protects the liberty of same-sex couples.

However, if the Court rules that laws like Prop 8 should be subjected to “heightened scrutiny” and when they are, it’s clear they violate the equal protection clause, that would also have long term national ramifications.

* Gay marriage, by the numbers: The Associated Press has a good rundown on all the basics. Here’s the target:

30: The number of states, including California, that ban same-sex marriage in their state constitutions. Ten states bar them under state laws. New Mexico law is silent on the issue.

A broad ruling in Prop 8 could reduce those numbers rapidly.

What else?