Why Tunisia's president is cracking down on political opponents, singling out black Africans and undocumented migrants

Black Tunisians and migrants are being targeted by racist rhetoric endorsed by their president. (Reuters: Jihed Abidellaoui)

Tunisia, the birthplace of the Arab Spring, now finds itself in crisis 10 years on.

After a decade of stalled progress, its economy is struggling and the government blames "illegal" African migrants for overrunning the country's limited resources.