* Wonkblog has a terrific series of charts that demonstrate the astonishingly rapid cultural shift underway on gay marriage, and as the charts show, it will only continue irrespective of the Court’s rulings.

* With DOMA set for a SCOTUS hearing tomorrow, a new CNN poll finds that 56 percent of Americans say the federal government should recognize same sex marriages performed in states that allow them, but only 28 percent of Republicans say the same.

I wonder how young Republicans answered this question, given the clear signs of a generational divide in the GOP on the issue.

* Steve Benen explains what’s important about Solicitor General Donald Verrilli’s rebuttal of Samuel Alito’s insistence that marriage rights should be left to “the people” to decide.

* Adam Serwer takes apart the arguments advanced by Prop 8′s chief defender, and boils them down to this: Opponents of gay marriage will ultimately lose in the long run, so why should SCOTUS push the process along?

* Openly gay Dem strategist Hilary Rosen on her on-air moment of realization that Ralph Reed believes her children would be better off if she weren’t their parent.

* Dave Weigel on how Chris Christie has found himself on the wrong side of the gay marriage issue even as marriage equality suddenly polls just as well in his state as he does.

* Francis Wilkinson has an amusing interview with Yale law prof Jack Balkin in which the two try to keep track of Antonin Scalia’s shifting approaches to interpreting the Constitution, depending on what’s expedient at the moment.

* About those red state Dem Senators who are too skittish to embrace background checks: Igor Volsky tallies up the gun murders in their states, and the huge number of upcoming gun shows in them where private sales will continue unchecked.

* Jamelle Bouie makes a key point: Whatever happens with Obama’s package of gun reforms, Newtown has changed the politics of guns:

What’s key about Sandy Hook isn’t that it yields new legislation, it’s that it inspires new activism around gun control, and provides energy for the long effort to build a political coalition unafraid of the cultural politics that surround guns. Sandy Hook — helped along by a new Democratic majority of urbanites and nonwhites — has changed the politics of gun control. It will just take awhile for us to see the effects.

The history of gun control clearly demonstrates that reform efforts can often take a long time and multiple tries before succeeding — the key development is that Dems are (mostly) coming to believe this is no longer a loser for them.

* With Senators Rand Paul and Ted Cruz threatening to filibuster gun legislation, the White House pushes back hard, claiming that would be an affront to families who have lost children to gun violence, a sign Dems won’t be gentle in their response if Republicans actually go through with it.

* Worth watching: Mike Honda and other Dem Reps. are pushing the Obama administration to defund a GOP measure that makes it harder for law enforcement to trace guns used in crimes.

* Uh oh. With South Dakota Senator Tim Johnson set to retire, Dems will now have to defend seven Senate seats in states Mitt Romney won last year.

* And Johnson’s retirement means Sherrod Brown could be the next chair of the Banking Committee, which would mean a much more aggressively populist committee that some financial lobbyists are already dreading.

With the choice possibly coming down to Brown or the far more bank-friendly Chuck Schumer, this will be closely watched by national liberal/labor groups and banks alike.

What else?

Greg Sargent writes The Plum Line blog, a reported opinion blog with a liberal slant -- what you might call “opinionated reporting” from the left.