What do the country folk of Wagga and the eastern suburbs sophisticates of Wentworth have in common? Not, you might think, that much, except that both signal a new era of independent threat to conservatives. The good burghers of Wagga showed that just over a month ago when they elected local independent Joe McGirr to replace the disgraced state Liberal MP Daryl Maguire, off a 28% swing against Gladys Berejiklian’s government. That was in the aftermath of the knifing of Malcolm Turnbull.

There won’t be a 28% swing against Dave Sharma tomorrow in Wentworth. But there “only” has to be an 18% swing for him to lose. Sharma, who parachuted into the seat from the North Shore, has done himself no favours by campaigning as though he’s entitled to the seat, rather than having to earn it (remember that “Sharma is the Liberal Obama” garbage peddled by Fairfax a few weeks back?). But this normally wouldn’t count against him in such a blue-ribbon Liberal seat. The problem is well above Sharma’s pay grade: such is voter disgust at the self-indulgence and right-wing leanings of the current Liberal Party, a centrist, well-known and well-regarded local can pose a major threat to them.

That means the cash-strapped Liberals, now without their major fundraiser and donor in Malcolm Turnbull, face the prospect of independent insurgencies in metropolitan as well as regional seats that should have required little in the way of attention and resources in next year’s election. If Julie Bishop leaves politics, don’t discount her loss either — she’s a ferocious campaigner prepared to go anywhere, anytime across the country for Liberal candidates. That will all leave less money and drawcards for marginal seats that have to be protected against Labor’s strong ground game.

Some of those independent-versus-Liberals contests will be particularly pointed: if Tony Abbott contests the next election, expect one in Warringah, one that might well topple a man widely reviled within his own party.

The Liberal hope would have been that after nearly two months, Wentworth voters would have got over the betrayal of Turnbull and be ready to move on. To make that sure that didn’t happen, they decided to end the campaign with the worst week any government has had for many years, combining (in the most charitable estimation) spectacular incompetence, panicked misjudgment, arrant stupidity, diplomatic bungling, and the Nationals deciding there hadn’t been a leadership blow-up for at least five minutes so it was time to have another one.

If Kerryn Phelps was an outside chance last weekend, she got a lot more competitive as each disastrous day went by for the Liberals this week, and must have looked a lot more attractive to the disgruntled Liberal voters who will likely form the basis of her support.

The Wentworth campaign began with Scott Morrison getting rebuffed by his own party when they opted for Sharma over a female candidate. It may yet end with an altogether worse humiliation. But Phelps is unlikely to be the last independent to turn a safe Coalition seat into a nailbiter.