<prompt> tafsiri zifuatazo kutoka kwa swahili hadi kiingereza.obasanjo alikataa kumpigia kampeni jonathan kwenye uchanguzi mkuu wa mwa nigeria wa mweaka 2015, ambapo rais wa sasa, muhammadu buhari alishinda.  <response>: obasanjo campaigned against jonathan in nigerias 2015 presidential election, which current president muhammadu buhari won. 