ANC deputy secretary-general Jessie Duarte hit the nail on the head when she slammed her party for failing to fight "tribally chauvinistic" tendencies within its ranks.

Her use of certain phrases may have been problematic - for instance, calling the ANC racist can only help to strengthen the arguments of white racists who are opposed to measures aimed at correcting the wrongs of the past - but the problem she is warning us against is real.

The political degeneration of the country's ruling party - a liberation movement that was at the forefront of constructing what we now know as the South African nation - is a threat not only to itself, but the nation-building project as a whole.

Speaking at a party meeting in Naledi, Soweto, at the weekend, Duarte said the ANC has "almost become tribalist" in the manner in which it marginalises those of its members who are classified coloured and Indian. This, she argues, goes against the party's core value of non-racialism.

She may have been talking about the party and its membership, but this problem is becoming prevalent throughout our society.

There is a brand of narrow nationalism that is threatening the very foundation of our democracy.

This is a chauvinistic nationalism that rejects Steve Biko's definition of "black" as inclusive of those that were classified as Indian and coloured under oppression. It is a brand of nationalism that also seeks to exclude white compatriots, no matter how committed they may be to the democratic project, from participating in the public life of our nation.

We see examples of these in the social media campaigns waged against people like public enterprises minister Pravin Gordhan and the opposition to the appointment of a new Eskom CEO purely on the basis of race.

All of this is not only in conflict with the spirit of our constitution, it is a threat to our nationhood. For if narrow nationalism is allowed to take hold today, to discriminate against this or that group of people because their skin tone is generally a shade lighter, tomorrow it will justify discriminating against more people because of the language they speak, the region they come from or the clan names they use.