If Pakistan's chief justice, Iftikhar Chaudhry, manages to press his charges of corruption against the president, Asif Ali Zardari, he will bring down the existing Pakistani government. If he extends his anti-corruption campaign to the political elites as a whole, he will bring down the entire existing political system – and replace it, his critics say, with a dictatorship made up of an unelected (and equally corrupt) judiciary.

The corruption charges against Zardari date back to the governments of his late wife, Benazir Bhutto, in the 1990s. Charges against him, the present prime minister, Yusuf Raza Gillani, and other leading politicians and former officials were dropped under the National Reconciliation Ordinance (NRO) of 2007: the product of a deal – allegedly brokered by the Bush administration – between the then military ruler, President Pervez Musharraf, and Bhutto in late 2007, which allowed her to return from exile and take part in elections.

In December 2009, the supreme court declared the NRO unconstitutional. The two years since have seen a slow-motion tug of war between the supreme court and the government. The main opposition party, the Pakistan Muslim League of Nawaz Sharif (PMLN), for quite a while did not push this issue very hard, in part as the result of a truce between its provincial government in Punjab and the Zardari government in Islamabad – but also, it is widely thought, because, given its own record, the PMLN has good reasons to fear judicial activism. The only leading opposition politician consistently to have backed the chief justice's campaign has been Imran Khan – and he has never been in government.

The truth is that Pakistani politics revolves in large part around politicians' extraction of resources from the state by means of corruption, and their distribution to those politicians' followers through patronage. Radically changing this would mean gutting the existing Pakistani political system like a fish. Nor is it at all certain how popular the process would really be with most Pakistanis.

For while the greater part of this process of extraction and redistribution is illegal according to Pakistani law, how much of it is immoral in Pakistani culture is a much more complicated question. Every Pakistani politician accuses his rivals of corruption but, equally, the perception that he himself is "generous" and "honourable" to his own supporters is likely to be central to his own local prestige. If a public monument is ever erected to the Ideal Pakistani Politician, the motto "He dunks but he splashes", originally coined by Mayor Richard Daley of Chicago, should be inscribed on its pedestal.

And this is not just a matter of cynical politics. It also obeys a fundamental moral imperative of local culture to be loyal to one's followers and, above all, one's kinfolk. The politician who is really despised is the kleptocrat who both steals immoderately and does not share the proceeds. As a result, a good deal of the proceeds of corruption does get distributed through parts of society, thereby helping to maintain what until recently has been the surprising underlying stability of the Pakistani political system.

The military is widely seen as relatively immune to corruption, and when it comes to its own internal workings, this is largely true – though it usually ceases to be true when generals go into politics. However, it is vitally important to note that this is in large part because for many decades the military as a whole has acted as a kind of giant patronage network, extracting a huge share of Pakistan's state resources via the defence budget and other concessions, and spending them on itself. Because – to its credit – it has distributed the resulting benefits in an orderly if hierarchical way among its generals, officers, non-commissioned officers and even to a degree privates, it has managed to keep a lid on corruption within the military itself. However, a belief is growing among ordinary soldiers, not just that the generals' perks are immoderate but that in some cases their families are using their connections to make huge corrupt fortunes outside the military.

As for Zardari, it seems highly doubtful that he can hang on much longer. The chief justice is pursuing him with bulldog determination and the letter of the law is on his side. The military has been infuriated by what it believes are his attempts to ally with Washington against it. It does not want another military government, but it does want a civilian regime that is much more responsive to its wishes. And the opposition want him out before, not after, senate elections that might just enable him to cling to the presidency even if as expected his Pakistan People's party is defeated in general elections due by early 2013. Whether getting rid of Zardari will fundamentally change Pakistani politics, however, is a very different matter.