POLITICAL animals in Delhi, the capital of the world’s biggest democracy, take a natural interest in elections to any of India’s 31 assemblies. Most states have populations the size of ordinary countries and so merit attention in their own right. But usually, as when the 64m people of Karnataka, a southern state roughly the size of France, vote for their own state’s government on May 12th, the rest of India wants to know what’s in it for them. Bangalore, the state capital, is among the richest and most dynamic of India’s cities. The campaign pits the two genuinely national parties against one another, the ruling Bharatiya Janata Party (BJP) of the prime minister, Narendra Modi, versus the Congress Party led by Rahul Gandhi. But even that cannot account for the fervour surrounding this contest. Why does the result of Karnataka’s election matter so much to the whole of India?

Campaigning last week in a coastal district, where tensions between Muslims and the Hindu nationalists of his base have run high, Mr Modi concentrated his attack against the incumbent state government, run by Congress. He spared a kick for the wider Congress party too, which has been on a remarkable losing streak ever since Mr Modi became prime minister in 2014. After its defeat here, Mr Modi boasted, the grand old party of India’s independence movement would be reduced to the “PPP”: P for Punjab, the only other sizeable state it governs; P for Puducherry, a territory which is truly piddly; and P for parivar, which means “family” and is intended to wound Mr Gandhi, who inherits his fame from the Nehru-Gandhi dynasty that has led Congress for most of a century. (This was also a whistle loud enough for deaf dogs: PPP being the name of a prominent party in Pakistan.) Congress needs to keep Karnataka more than the BJP needs to win it. Mr Modi is closing in on his stated goal of making India a “Congress-free” federation of states, even ahead of the next election for the national parliament, expected in early 2019.

The symbolic value of victory in Karnataka, however, pales in comparison next to the practical value of owning the state’s political apparatus. India’s elections have become frightfully expensive. Campaign spending in the parliamentary election of 2014 is reckoned to have cost $5bn, more than twice as much as the previous election and next year’s should be the world’s costliest, barring only the sort put on by 21st-century Americans. Unlike in America, though, the vast majority of India’s spending is kept off the books; unrealistically restrictive limits mean that, technically, almost the whole of an electoral war-chest is illegal. Control of a government is essential for keeping open the flow of “black” or undeclared money that makes a campaign tick. States have their own law-enforcement agencies, for one, and a state like Karnataka has big budgets for public projects (indebted Punjab does not).

No politician from any of India’s larger parties can say this aloud. Indeed the parties, viciously competitive in most fields, tend to conspire when it comes to keeping mum about the ugly business of campaign finance. Against that trend, the BJP’s first prime minister, Atal Bihari Vajpayee, once acknowledged that “every legislator starts his career with the lie of the false election return he files”. The stables are in desperate need of cleaning, starting with a bit of sunlight. But there is no prospect of any such reform in the short term—hence the high stakes this week. And if the BJP manages to take Karnataka from Congress, it may well nip in the bud whatever hope the opposition has to retake control of the national government next year.