The Gang of Six, according its participants, were extremely close to striking a bipartisan debt-reduction deal, and taking the particulars to their respective caucuses. The process broke down, and largely imploded, once Sen. Tom Coburn (R-Okla.) moved the goalposts, brought up a bunch of new demands, and ignored previous measures that he’d already agreed to.

It’s almost as if a far-right Republican was concerned that a deal was coming together, so he had to scuttle his own progress.

As Matt Yglesias explained very well, this keeps happening.

Bipartisan talks begin on the Hill. They make progress. Sometimes a little progress, and sometimes a lot of progress. Then at some point during the progress-making, the conservative participants in the talks realize that they have a problem — the talks are making progress! So then they start casting around for new demands or new reasons to break off the talks. Eventually, Lucy yanks the football away and we’re back to square one. You can critique the motives or behavior of Tom Coburn (debt) or Lindsey Graham (immigration, climate) or John McCain (Gitmo, climate) or Bob Corker (financial regulation) or Chuck Grassley (health care) on some individual deal or particular gang. But the repetition of the story strongly suggests a structural issue.

Quite right. And that structural issue isn’t a mystery — it’s called “Mitch McConnell’s approach to policymaking.”

Indeed, the Senate Minority Leader has occasionally been quite candid about his thinking. A year ago, for example, he explained his decision to try to kill health care reform from the outset, regardless of merit or Democratic compromises, by demanding unanimous Republican opposition: “It was absolutely critical that everybody be together because if the proponents of the bill were able to say it was bipartisan, it tended to convey to the public that this is O.K., they must have figured it out.” It’s a dynamic that made compromise, quite literally, impossible.

Soon after, McConnell explained the importance he and the House GOP leadership put on “unify[ing] our members in opposition” to everything Democrats propose, because unanimous Republican disagreement would necessarily make Democratic ideas less popular. “Public opinion can change, but it is affected by what elected officials do,” McConnell conceded. “Our reaction to what [Democrats] were doing had a lot to do with how the public felt about it. Republican unity in the House and Senate has been the major contributing factor to shifting American public opinion.”

The way McConnell sees it, for much of the American mainstream, “bipartisan support” is akin to a national seal of approval. It must be good, the thinking goes, if both sides agree. Likewise, there must be something wrong with partisan ideas — after all, if they were sensible proposals, negotiated in good faith, then both sides would like it.

The “structural issue,” then, is Senate Republicans putting elections above governing. Bipartisan talks have to fail, or the GOP’s strategy falls apart. The goal isn’t to strike deals, it’s to kill deals and blame Dems for a lack of bipartisanship. Create favorable electoral conditions so the GOP can win is the only thing that matters. Period. Full stop.

As the Senate Republican leader has admitted, “Our single biggest political goal is to give our nominee for president the maximum opportunity to be successful.” Is it any wonder, then, that bipartisan negotiations keep falling apart?