Republicans have been itching for the match-up between Joe Biden and Paul Ryan since the instant Romney put Ryan on the ticket, if not before. Their confidence that the contest will end in a lopsided victory makes Chris Christie's optimistic pronouncements about the first presidential debate seem downright reserved by comparison:

I think Ryan's going to eat him alive.

And, hey, Christie turned out to have been right, though the mechanics of transforming Obama's lackluster performance into the devastating loss the pundits keep talking about largely depended on the dismal expectations they held for Romney. Going into Thursday's debate, Ryan instead walks on the brittle hopes of an emboldened GOP. Biden just walks.

Biden does not raise the ire among conservatives that Dick Cheney did with liberals; his peculiar charm is to come across as basically competent and up to the job, but without the desire to wield even more power. Republicans do not joke about his cold, black heart and maniacal lust for world domination; one cannot picture him shooting a friend in the face, unless it is with a SuperSoaker. (Imagine Cheney brandishing a toy gun around children without them screaming in terror.)

No, the jokes the right makes about Biden have to do with his clumsy malapropos and rambling metaphors; his speechifying tics ("literally", multiple and contradictory references to his rough childhood) give them TMJ but don't ignite conspiracy theories. They anticipate his debate against Ryan not because he seems to be a worthy foe against whom a hard-fought victory would signify a triumph of ideas, but because they think Ryan will steamroll the guy.

Still, Biden has a core strength that could prove Ryan's undoing: loyalty untrimmed by ambition. Sure, Biden has found his level in the office of the vice president a wading-pool of influence that Ryan seems to already have judged too shallow for his burgeoning empire of ideas. Biden is content to be regional district manager with a window in his office; Ryan dreams of the corner executive suite (or in this case, the executive suite with no corners). Ryan wants to win, Biden wants his team to win. Biden will take one for the team, no questions asked (he went on stage with Sarah Palin); faced with contradictions between his ideas and his running mate's, Ryan just refuses to take questions.

Biden's willingness to take orders smoothed over the one instance in this presidency where his exuberance overwhelmed his faithfulness: his ahead-of-the-Obama-curve endorsement of same-sex marriage. In general, Biden's excitement is in service of the president: every success is a "Big Fucking Deal".

Ryan lacks the same level of enthusiasm for Romney, much less his policies. Ryan made a name for himself in Washington by flacking a budget proposal too conservative for Newt Gingrich – so bold (even reckless) that it didn't need a spokesman so much as a target. Ryan's championing of his budget allowed other Republicans to endorse its radical ideas without being tainted by their decidedly unfriendly ideas. When Romney picked Ryan, he hoped to capitalize on the gusto of Ryan's rhetoric, but duck its policy prescriptions. Ryan has thus far been uncomfortable, but tolerant, in his role of help-meat, trading his details and "roadmap" visions for generic campaign stumpery.

Ryan's success as a running mate has been in direct proportion to his willingness to emphasize style over substance, putting Biden in the unlikely position of wanting his debate opponent to engage on real issues – and to be the beneficiary of a talkative antagonist. If Biden does exactly what Obama did in the last debate, and just let Ryan motor on, the chances are all the greater that Ryan will say what he actually believes – so much of which is heroically unpopular with American voters – and with Mitt Romney. (Ryan is far to the right of most Americans on social issues, just to the right of Romney on the same; when it comes to fiscal policy, he's barely in the same universe as Americans, though, to be fair, at least he exists in a place with recognizable laws of logic. Romney's math floats alongside invisible numbers in an alternate reality.)

Romney emerged from the first presidential debate with the wind at his back almost entirely because he took advantage of the national audience to turn swiftly away from the anger and base-baiting politics that characterized his campaign through September. Ryan has had less practice at shaking his personal Etch-a-Sketch than Romney has, and has shown less interest in it. He's more of a paint-by-numbers guy.