Hillary Clinton appears, by the polls, to have won (the CNN poll, just in, is scoring it 57% Hillary to 34% for Trump), and Donald Trump to have “not lost” the second US presidential debate, a bizarre affair advertised as a “town hall”-style event, in which few audience members got the opportunity to ask a question. And in which Trump threatened, if president, to appoint a special prosecutor and “use the laws” to put Clinton in jail.

Despite such bizarre tangents, and with the pressure on Trump following the release of the weekend’s Access Hollywood tape, which recorded him trading trash talk about women and sleazy ruminations on sexual assault (“grab her pussy”), Trump managed to turn in a combative if frequently incoherent performance, which nevertheless managed to frame Clinton as a political insider who had had decades to solve problems that she now promised to address.

[Rundle: Trump boasts of ‘grabbing pussy’, GOP ducks for cover]

Clinton, meanwhile, was low energy and failed to mount an effective attack against Trump, or much of an effective defence against some of his wilder charges. The debate was oddly dissatisfying, with Trump becoming increasingly freewheeling as the evening went on, while Clinton withdrew to an often defensive and slightly halting response. Perhaps this was part of the Clinton plan — to let Trump expand into the space and thus expose himself as a mentally disroganised rambler. If so, mission accomplished, but in doing so it made him look the more commanding of the pair, However it’s scored, Trump did well enough to dispel notions of being replaced on the ticket in some desperate last-minute switch by the Republican Party.

Which, some have been suggesting, was the whole point of Hillary’s performance — to give the Donald a pass, and keep him on the ticket.

The thing began innocuously enough with Clinton making some vague point about America having to be “good to be great”, while Trump confessed his embarrassment at the material on the Access Hollywood tapes. Then the gloves came off as Trump pivoted from his scandal troubles to his character — “no one respects women more than I” — to being able to fight Islamic State. Trump went into a recitative about all the problems of the world, which only he could solve, and that Hillary Clinton had had 30 years to solve. Clinton replied with her own list, from birtherism to mocking the disabled, and Trump went on the attack about missing emails, and that’s when he threw in the prison threat.

When it moved onto Obamacare, Clinton had a series of concise answers on policy shift, and Trump went into salesman mode: “It’s going to be so good …” One answer out of two, Trump lost whatever thread he had started on and rambled through a mix of opinion, outright falsehoods — Russia is new to nukes, I was against the Iraq war, too many to list — and wound up supporting Assad’s actions in Syria against Islamic State, and criticising his V-P candidate Mike Pence, who is in favour of US strikes against Assad: “I disagree with him.”

“Hillary has a lot of hate in her heart,” he later said, in relation to Clinton’s “basket of deplorables” speech, once again turning the tables on Clinton. Throughout, the debate Trump prowled the stage with a Caeser-is-angry expression on his face, while Clinton stayed on her stool and adopted expressions that were variously pained, amused, agape, can-you-believe-this-guy, a full Showcase portfolio of affects.

The final question was the usual dickwit one that rounds out these things: what quality do you admire in each other. Hillary: his children. Trump: she’s a fighter, she never gives up. Trump’s answer was the less cute — but it gives him leeway to use it in rallies. “Sure she never gives up. Never wins, but she never gives up,” etc etc. With that, they shook hands and parted, the cams following them recording, grimly hilariously, a symmetry: two powerful families walking from studio through corridors to garage, to climb into identical cars, surrounded by Secret Service protection.

A nothing end to a nothing evening, anything resembling a real issue of policy or character slipping away without real answer. It’s evenings like this — watched in a sports bar where everyone was as flat and dispirited as I — that even the most gonzo joy in the carnivale fades. Badly designed, badly conceived, badly run, it featured one candidate who is simply a terrible and deranged human being, and another whose apparent limited ability to marshal and prosecute an argument against a blowhard loser, to finish the damn guy off, suggests real limits of ability.

There was just an enormous vacuum there where a real and vigorous engagement should be. The fault is largely Trump’s because he has no real policies or complex ideas — but a functioning democracy should be able to call out a know-nothing, not allow him to indulge himself.