* Jonathan Chait makes the case that shifting demographics really may translate into a long term Democratic majority, one rooted in the theory that the old racial and cultural divisions no longer automatically favor the GOP.

* The Obama administration will delay implementation of a key piece of Obamacare designed to provide affordable health coverage to small businesses and employers.

The move brings to mind this essential Ed Kilgore post warning liberals to be wary of Obamacare triumphalism and to take the challenges of Obamacare implementation very, very seriously.

* Another one: Conservative Dem Senator Bob Casey of Pennsylvania announces his support for gay marriage, joining at least half a dozen other Dems who have rushed to get in under the wire of history.

* Steve Benen tallies up the remaining eight Senate Democrats who have still failed to endorse marriage equality. Meanwhile, exactly one GOP Senator has come out for it — Rob Portman, whose shift was supposed to be a seminal moment for the party.

* Peter Beinart on why the GOP is better off embracing Bill O’Reilly’s cautious (if opportunistic) acceptance of the reality of public opinion on cultural issues rather than Rush Limbaugh’s continued railing against the inevitable.

* Jennifer Rubin has an excellent post on why social conservatives are losing the fight over gay marriage, and what it says about the long term perils the right wing media bubble poses to the GOP and conservatism.

* As Dave Weigel notes, Marco Rubio’s claim that we must “slow down” on immigration reform is only the latest effort to create a scapegoat in advance for failure, should the heat from the right force Republicans to bail.

* Joan Walsh on how Rubio is putting the Tea Party over Latinos, and why he’ll side with the former if forced to make the choice.

* Jonathan Capehart skewers the emerging meme that Obama failed to push hard enough for gun reform, and rightly insists that the American people really need to provide him with backup and demand Congressional action.

* Senate Dems release a Web video featuring Senate Republicans murmuring (just after Newtown) that, yes, we must act to fix the background check system, a move designed to pressure them into actually doing that.

* Mark Follman debunks the NRA’s mythology about gun free zones creating mass shootings.

* The NRA’s Wayne LaPierre recently compared background checks to a speed bump, prompting this apt response from Mark Glaze of Mayors Against Illegal Guns:

Speed bumps are in fact an excellent metaphor for gun background checks — but LaPierre is wrong about their value. Both speed bumps and background checks save lives, and neither imposes much burden on people going about their business. If anything, the background check system should function more like speed bumps do: they apply to everyone equally.

ICYMI: My question for Senators who oppose expanded background checks.

* And Rachel Weiner talks to the gay son of a Republican Congressman whose own child’s sexual orientation was not enough to shift his opposition to gay marriage.

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.