IN A hut on stilts on the island of Borneo, a dozen skulls hang in a cage. They are those of long-dead victims of the Dayaks—indigenous tribes whose members make up the majority in Sarawak, a sprawling Malaysian state. Once thought to harbour protective spirits, the heads are now tourist curios. Few indigenous people still live in the communal dwellings such relics guard, and those who remain hang Christian crosses on their doors. This month many Malaysians would like to see the Dayaks take one last scalp. Sarawak’s state election on May 7th is a chance for voters to rebuke Najib Razak, Malaysia’s unpopular prime minister, who has spent much of the past year denying that hundreds of millions of dollars which entered his bank accounts were wangled from an ailing national investment firm. Investigations into 1MDB’s dealings are under way in half a dozen countries; some of its borrowings are in default. Yet parties loyal to Barisan Nasional, Mr Najib’s coalition, will probably retain a crushing majority in Sarawak’s state assembly. That prospect illuminates the prime minister’s resilience, which outsiders find bizarre.

Sarawak is one of two Malaysian states in the northern part of Borneo, abutting the tiny kingdom of Brunei. Matters which enrage voters in Peninsular Malaysia, 500 miles (800 kilometres) across the sea, often feel distant. Victor, a shopkeeper in the town of Bau, says he doesn’t know much about 1MDB: it is “a national issue”, not a local one, he explains. Instead, the topics that irk Sarawakians include shabby road and power networks, land-grabbing loggers and the royalties which Petronas, the state oil firm, pays for access to its wells.

Maintaining Sarawak’s support is becoming essential for Barisan, which in various forms has ruled Malaysia since independence in 1957 but whose popularity among urbanites is collapsing. Mr Najib has visited the state more than 50 times since 2009, impressing locals. Sarawak’s biggest party, the PBB, forms the second-biggest bloc in Mr Najib’s federal coalition; half of its MPs hold cabinet posts. At the general election in 2013, parties from Sarawak delivered 25 seats to the government—whose winning majority was just 22.

Lucky then that polls in Sarawak hand the incumbent a huge advantage. Limited access to the internet means state-controlled newspapers retain great influence. Canvassing the vast interior is hard without helicopters or speed boats, observes James Chin, a political scientist. Years of gerrymandering have doubled the size of the state assembly. Loyal Malay-Muslim areas enjoy a glut of seats; rebellious ethnic-Chinese ones suffer a paucity. Of 11 new seats being added this year, Barisan will snap up ten.

Unsophisticated rural voters are routinely bought with gifts of cash and other goodies. Sanjan Anak Daik, a candidate from the opposition Democratic Action Party, says some are led to believe that grants and subsidies can be demanded back if they vote against the government. An old man waiting for treatment at a grotty clinic in the small town of Siburan—a stop on Mr Sanjan’s campaign trail—says the opposition will never win if all they hand out is leaflets.

This year Barisan is also getting a legitimate boost from the wild popularity of Sarawak’s newish chief minister, Adenan Satem. A survey in January found that Mr Adenan’s approval rating has climbed above 80%; billboards near Kuching, the state capital, boast that “Adenan fever” is rife. In part voters are simply pleased to see the back of his predecessor (and former brother-in-law) Taib Mahmud, who held power for three decades and on whose watch Sarawak’s precious rainforests were plundered. But he has also softened up locals with a barrage of populist policies, including an end to toll roads and new protections for the environment.

His canniest move has been to back growing calls for the federal government to grant Sarawak greater autonomy, co-opting a cause long championed by the opposition. Playing up the state’s distinctiveness has helped Mr Adenan argue that 1MDB’s woes are not relevant to Sarawakians—and to ban from Sarawak scores of opposition figures who, he hints, will bring problems from the peninsula. Opposition parties, for their part, have made a tough job trickier by squabbling over seats, resulting in undignified multi-cornered fights.

Mr Najib’s coalition will sweep the polls. The victory will probably be peddled as proof that the prime minister retains popular support. But the government’s advantage in Sarawak is slowly eroding. Barisan’s share of the vote fell from more than 70% at state elections in 2001 to only 55% in 2011, notes Faisal Hazis, an academic. An old man sitting outside a shop in Siburan says this election is creating more hullabaloo than usual. He thinks the opposition has given locals a much better understanding of how their state is run.

The big opportunity for Mr Najib’s opponents is not to oust Sarawak’s immovable rulers, but gradually to weaken the state’s allegiance to Barisan. Among other disenchantments, Sarawak’s many Christians are disturbed by the Malay-Muslim chauvinist rhetoric which Malaysia’s government increasingly tolerates. If federal elections keep getting tighter, Sarawak’s MPs may be tempted to defect—dumping Barisan from power in exchange for more autonomy or a greater share of oil. For years a firm friend of the ruling party, Sarawak may one day think for itself.