For the past four decades there has been a recurring motif in Nigerian politics. A new government takes power on the crest of popular approval but soon falls short of expectations.

The sequence started with Shehu Shagari's National Party of Nigeria government, which was then overthrown by General Muhammadu Buhari in December 1983. Buhari's regime was overthrown in a palace coup by General Ibrahim Babangida in August 1985. A popular uprising followed the annulling of an election in 1993, and General Sani Abacha seized power. After the restoration of constitutional rule, Olusegun Obasanjo was elected president, handing over in 2007 to Umaru Musa Yar'Adua, who died in 2010, leaving his Vice-President Goodluck Jonathan to take over. By 2014, popular opinion had moved decisively against Jonathan and he was overwhelmingly defeated by Muhammadu Buhari in 2015.

On each occasion, Obasanjo, in his role as a 'founding father', has published an open letter criticising the incumbent and calling for change. And change has duly happened. His letter of 24 January urging Buhari not to seek re-election next year continues the theme. So far, the response from officials in Abuja has been muted irritation but activists in the governing party are likely to take it much further, given Obasanjo's influence. If nothing else, it has opened up the debate about the country's political system, the quality of governance, and accountability.