For a while, it looked like the Republicans would get sucked into the soap opera of Sarah Palin’s family. It briefly looked like they’d made that Democratic mistake of picking a candidate whose ‘colourful’ background would become the only story that mattered — an Eagleton or Ferraro.

But then she produced one of the great Republican speeches. If the GOP somehow win in November, history will mark that speech as the turning point.

Not that it was particularly wonderful in itself. It was virtually content free, except for an invocation to drill more (no puns please) and detail of her family life with Track, Trig, the aptly-named Bristol and assorted other relatives. But it energised a convention that between a hurricane, a diabolically unpopular incumbent and a Methuselah-like candidate had lacked any spark or spirit.

And she was funny. Even the rusted-on Obamaniacs at The Guardian admitted that the girl done good. That line about how the presidency was not supposed to be “a journey of self-discovery” was a killer that cut right to the heart of Barack Obama’s self-obsession.

And it finally connected the Republican campaign to something going on in the real lives of Americans.

Despite the whoops and cheers, Palin was at odds with her audience. If you watch her speech, you can examine the Republican delegates close up. Mostly white, rich and old. Palin’s kids were the youngest ones there by a long stretch. And while there was the occasional Asian face, African-American delegates were almost impossible to spot.

The party of Lincoln. The party of rich white men and their dyed-blonde — or white-haired — womenfolk. The party of Dubya — the third generation of a political dynasty, and the worst of the lot. The party of Big Capital, the best party money can buy.

Palin isn’t from round those parts. She’s from small-town America, a white America where they work hard for a living even if they’re middle-class, where they call it “Eye-rack”, where they lick their hands and wipe babies’ hair down, where they regard big corporations, even if they work for them, as every bit as much the bad guys as gays and abortionists — and probably worse.

She’s from Mike Huckabee’s Republican party, but more presentable. She might be a religious fundamentalist, but she’s not scandalised by a pregnant daughter. Everyone knows teenagers aren’t always careful — and they probably weren’t themselves, or maybe their parents weren’t. That’s life.

From Palin, the rhetoric about reform, about government being too big, works. It couldn’t come from a Republican insider, a senator, or someone linked to the profligate Bush Administration. She can run as an outsider, as an authentic voice for change, even more so than McCain, whom she subtly placed in contrast to their own party’s Establishment. When she attacks the elites, it’s not just the inevitable liberal media you suspect she has in mind, but a lot of leaders in her own party.

If her selection short-circuited the “experience” argument against Obama — and I’m not convinced it does, because her inexperience is on the bottom half of the ticket, not the top — it may also have derailed the Democrats’ tactic of linking McCain to Bush, because McCain-Palin are bidding for the outsiders’ status themselves.

It’s not just evangelicals that Palin brings, it’s the Republican Party of white working class and middle-class Americans, a party a long way from the “comfortable committee chairmen” at whom Palin sneered, a party unimpressed with Washington powerbrokers, a party with an inbuilt suspicion of politicians, unless they’re like themselves.

Such people sent the “Republican Revolution” to Congress in 1994 and watched as their representatives stagnated, compromised or chased Clinton’s infidelities rather than fixing government. They voted for Dubya twice only to watch him flounder and blow the Federal budget. Palin viscerally connects with such people, in her voice, in her attitude, in her family, in the same way that Obama channels the craving for a new politics amongst Americans despairing of the Bush era.

Whether Palin performs as well without a teleprompter and a White House speechwriter remains to be seen. But the more she gives voice to her own values and those of her party, the more natural and appealing she will be. She will be a scarily effective representative of her constituency. Whether that constituency is big enough to still swing elections, however, is one of the key questions between now and 4 November.

At least we know she’s no Dan Quayle. Win or lose, Palin has arrived on the US political scene and won’t be going away any time soon.