This paper follows my (and my Colleagues’) articles analysing the current surge of populist-nationalist political elites in Central Eastern Europe, especially in Poland and Hungary, where these elites had won multiple elections and entrenched themselves politically. While the previous papers discussed political styles and strategies applied by populist leaders in their successful campaigns, as well as the outcomes of their rule, especially the deteriorating performance and the “quality/effectiveness of governance” (as reflected by falling WGI scores), this paper focuses on the key explanatory factors related to “political elite decay” – the deteriorating political skills, competence and qualities of political leaders and elites, as displayed by the ruling populist nationalists in Poland and Hungary. In line with the elite-centred approach, the paper argues that this “political elite decay” should be seen as the main (though not necessary the sole) determinant of the accompanied “political-institutional decay” and deteriorating quality/effectiveness of governance.