Also in the early 1990s, Italy faced significant challenges, as voters – disenchanted with political paralysis, massive public debt and the extensive corruption system (known as ''Tangentopoli'') uncovered by the Clean Hands (''Mani Pulite'') investigation – demanded radical reforms. The scandals involved all major parties, but especially those in the government coalition: the Christian Democrats, who ruled for almost 50 years, underwent a severe crisis and eventually disbanded, splitting up into several factions. The Communists reorganised as a social-democratic force. During the 1990s and the 2000s, centre-right (dominated by media magnate Silvio Berlusconi) and centre-left coalitions (led by university professor Romano Prodi) alternately governed the country.