The debate on the issue of free and fair election has dominated public discourse by scholars and observers of Nigerian politics due to controversial nature of election and democratic process in Nigeria. However, the 2007 and 2015 elections presented a unique case of electoral politics in Nigeria as both elections were conducted under different political leadership and INEC headship with different approaches to political power and election. This study argues that, what makes the difference between the 2007 and 2015 presidential elections in Nigeria, are leadership disposition to power, the rule of law and whether they are interested in re-contesting election or not: these are critical factors that has either boosted or marred the quality of election and determined level of effectiveness or ineffectiveness of INEC in both 2007 and 2015 elections, rather than the over-exaggeration of INEC chairman's integrity, initiatives and professional competency in both elections