The effectiveness of party president Mmusi Maimane has been questioned by the DA’s own researchers. Controversies swirl around senior party figures, including Western Cape Premier Helen Zille and City of Cape Town mayor Patricia de Lille.

The DA’s strong performance in the 2016 local government elections was built on hypermotivated white voters in Gauteng and their coloured counterparts in the Cape. It is ironic that tribalism in politics is now exhibited most visibly by the DA. But it is wrong, if tempting, to attribute all the party’s problems to racial politics.

Ideas matter. Some party activists remain wedded to the curious variant of liberalism that guided the Democratic Party. The current leadership includes one prominent proponent of creationism and homophobia, a black consciousness activist, and a champion of xenophobia and free market access to hair products. No wonder electors are confused.

Certain key factors explain the resilience of swaggering, dominant parties such as the ANC. They make full use of the advantages of incumbency, shamelessly allocating jobs, contracts and state resources to party supporters. Their seemingly inevitable victory discourages office-seeking politicians and energetic volunteer activists alike from supporting any other party. Right now, it is still the ANC that offers a route to national office. What rational, young politician would join a party that cannot reliably deliver a seat?

Opposition parties such as the DA and the EFF adopt “noncentrist” policies that do not appeal to typical voters. Because candidates and activists joined with little hope of winning, they tend to be a bit crazy: many of them are ideologues, extremists or sociopaths, such as Julius Malema or Zille. Socioeconomic concerns preoccupy most South African citizens. The DA is obsessed by corruption and a narrow swathe of urban and peri-urban policy issues. Opposition leaders such as Zille indulge in ideological posturing that they must know is damaging to their parties’ electoral prospects.

The DA is also trapped by its funders. It has allowed commercial farmers to waste water resources at great cost to the Western Cape’s economy. The party has bowed and scraped before these dinosaurs, and such grovelling can only be explained by party donations.

The DA’s credibility will rest on its coalition-building strategy. It has benefited handsomely from previous liaisons with the Inkatha Freedom Party, the National Party and the Independent Democrats. But the DA’s alliance of convenience with the EFF is destined to fall apart in the very near future, generating great animosity.

The ideological distance between the two parties will grow if Cyril Ramaphosa keeps occupying more of the political middle ground. Who will be the DA’s partner now?

The DA and the EFF will have to be more ruthless if they are to continue to grow. They need to find out where the rough centre of ground in SA politics lies, drag themselves towards it, message smartly to different constituencies and silence their egregiously self-indulgent leaders.

• Butler teaches public policy at the University of Cape Town.