* Paul Krugman on the fundamental contradiction underlying GOP opposition to Obamacare: If the law is a disaster-in-waiting that will surely collapse under its own weight, why the desperation to derail it before it kicks in?

* Conservative groups are lining up behind a new measure that would defund Obamacare and cut spending below sequester levels, another sign it may be impossible for House GOP leaders to pass anything funding the government.

To be clear on what’s happening here: GOP leaders offer a bill to fund the government at sequester levels with a defund-Obamacare rider attached. That can’t pass. Conservatives respond with a bill that itself defunds Obamacare and cuts spending even more.

* As Jonathan Chait notes, it’s gotten so bad for John Boehner that he is is now reduced to asking the President and Democrats to play-act assigned roles in the hostage drama conservatives are demanding.

* I very much agree with David Atkins: Dem candidates in 2014 can be counted on to make the stakes of Obamacare repeal very clear to voters, and while it may take time, it will ultimately prove a political loser for the GOP.

* Steve Benen punctures the “Putin is having his way with Obama” meme that’s suddenly so ubiquitous.

* Ron Brownstein highlights the real political risks for Obama if he gets drawn into an endless stretch of diplomatic wrangling that doesn’t end well for the U.S.

* Ezra Klein reports that the White House is denying labor’s request for fixes to the Affordable Care Act. Expect more on this next week, but for now, this looks like it’ll be a headache just when implementation is rolling out.

* Charlie Cook on why Dems should worry about the 2014 elections: Keep an eye on Obama’s lagging approval ratings, and on the lagging economy.

* Interesting: Larry Summers quietly tried to woo Elizabeth Warren behind the scenes, apparently for her support in the battle for the Fed. By the way: Be cautious of reports saying Warren, whose word will obviously carry weight given her stature as an advocate for Wall Street accountability, will definitely vote No on Summers. Not sure a decision’s been made.

* David Sirota on how the Colorado recalls are above all a reminder liberals must keep up the fight against the “gun rights” brigade’s demagoguery.

Will pundits take note if Mary Landrieu and Kay Hagan are reelected despite voting for Manchin-Toomey?

* Relatedly, don’t miss Zach Beauchamp on a major new study finding a correlation between gun ownership and murder. Cue up the “gun rights” brigade’s smoke machines…

* And I don’t think I can top Ryan Grim’s headline, so without further ado: “Here’s the passive-aggressive payback legislation dinging David Vitter for his prostitution scandal.”

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.