Urging her supporters to unite behind Barack Obama's presidential bid at the Democratic Party Convention on Tuesday, Hillary Clinton declared: "No way, no how, no McCain". It is a slogan that might well be applied to our own presidential candidate, Jacob Zuma, should he persist in his efforts to ascend to the presidency by anti-constitutional means.

Zuma seems determined to occupy the highest office of state by hook or by crook. The crookery involves a so-called "political solution" to his corruption charges, with options ranging from the National Prosecuting Authority (NPA) being pressured to drop the charges, to the Constitution being amended to give Zuma some form of amnesty or immunity from prosecution.

Yunus Carrim, the ANC's chairperson of Parliament's justice committee, has called for a political solution that is "legally and constitutionally tenable". But this is a contradiction in terms. There is no such thing as a "legally and constitutionally tenable" political deal, since any attempt to delay or prevent Zuma from standing trial on corruption charges, or to find a political way out of a legal matter, would undermine the principle that all are equal before the law. Once we place a politician above the law because of his status, we irreparably undermine our constitutional democracy.

Astonishingly, the idea that Zuma should get special treatment is gaining support, even outside of the ruling party and its alliance partners. The proponents of this view argue that Zuma's trial (and the possibility he may be convicted) would render our country politically unstable.

In the Mail & Guardian last week, the chief executive of Business Unity South Africa (which represents 80% of businesses), Jerry Vilakazi, was quoted as saying: "This matter [of Zuma] must be brought to closure so that the country can proceed with certainty of political leadership. If it requires a political solution, let a political solution be found".

The central committee of the South African Communist Party (SACP), meanwhile, has claimed that the continuation of Zuma's trial poses a threat to political stability in that it "unduly raise[s] the political temperature...in a manner that can negatively affect...stability...and democracy".

This is political blackmail, as several commentators have noted. Who is going to threaten stability or raise the political temperature if Zuma's trial proceeds? It is usually the very people who are warning of instability and civil conflict. They issue threats and then piously raise the alarm about the consequences, as if they have the country's interests at heart. Such threats are in themselves unconstitutional.

The first duty of any citizen who wants to secure South Africa 's stability is to defend the Constitution. If Zuma and his allies are concerned with political instability, why do they speak and act so recklessly in defence of their leader, attack the judiciary and incite mob behaviour? If the ANC Youth League and the SACP are concerned with stability, then why don't they desist from these tactics and allow the law to take its course? Indeed, why do they persist with Zuma's candidacy?

Clearly, the best outcome for South Africa would be for Zuma to remove himself from the presidential race until a court of law has delivered its final verdict in the case against him.

In any event, the stability argument for a political solution is clearly a bogus one. Firstly, a political deal would threaten constitutional democracy in South Africa by circumventing the rule of law and the principle of equality before the law; without which there is a far greater risk of South Africa descending into lawlessness.

Secondly, a political solution would smash the founding compact of our democracy by elevating the narrow interests of the ANC's ruling clique over the sanctity of the Constitution. Democracy can only and ultimately be safeguarded by constitutionalism, which recognises that democratic and accountable government must be coupled with constitutional limits on the ruling party's power.

Thirdly, a political compromise would deligitimise two key institutions of democracy: the judiciary and the National Prosecuting Authority. A political rather than a legal settlement would make it extremely difficult for the NPA to prosecute politically sensitive cases in future.  By sidestepping the courts, the authority and legitimacy of the judiciary would be permanently dented, and the principle of separation of powers (between the legislature, the executive and the judiciary) would be rendered meaningless.

Fourthly, by undermining confidence in public institutions, a special deal for Zuma would cause uncertainty and instability, thereby increasing political risk and potentially leading to foreign disinvestment.

Finally, without actually hearing the merits of the fraud and corruption case against Zuma, and without having seen the charges against him tested in a court of law, we will be denied the opportunity to assess - on the basis of a court judgment - his probity and suitability for public office.

This would set an intolerable benchmark for public life in South Africa by paving the way for individuals with grave allegations of public misconduct hanging over their heads to assume office without having to answer their accusers.

Where these individuals are given the opportunity to defend themselves in an impartial court of law, but actively avoid doing so by dragging out the legal process through endless pre-trial appeals or by trying to skirt the courts altogether, the cloud of public doubt will hang particularly heavily over their heads.

Zuma and his backers are no great friends of the Constitution. In fact, they view it as their enemy; as the one thing that stands as an obstacle in their path to absolute power. Zuma himself has said: "The ANC is more important than even the Constitution of the country".

By this he means that he is more important than the Constitution, since he and his clique conflate their own personal interests with the ANC's. This notion of "the higher law of the ruling party" taking precedence over the law of the country and the duty of judges to interpret that law is the greatest risk to the future of constitutional democracy.

In short, a political deal for Zuma would amount to a rejection of the Constitution, and accelerate the decline of constitutionalism in South Africa . This is a far greater risk to our country's stability than anything Zuma's backers can threaten. We must stare the political blackmailers down, at this early stage in our democracy, and reject their threats decisively, once and for all.

This article by Helen Zille first appeared in SA Today, the weekly online letter by the leader of the Democratic Alliance, August 29 2008

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