Prodi's coalition is a gamut of nine parties � running from two Communist parties at one extreme to liberals and Catholics at another � all of them unable to agree either on political ends or on means. It should be child's play for Berlusconi or any opposition to bring down such a government and return to the routine of the last 50 years, in which Italian prime ministers have come and gone in rapid succession as though through revolving doors.The famous fact is that during the immediate post-WWII era, Italy had something like fifty governments in fifty years (The Donnas beat that pace by a wide margin) which seems excessive. This "instability," however, masked a great deal of underlying sameness. A single political party was the dominant force in all the governing coalitions during that period. What you had was personnel turnover -- a lot of cabinet shuffles due to personal or factional in-fighting or the machinations of minor parties. But new cabinets tended to include many of the same people as the previous one (possibly in a new job) and someone who got booted out of cabinet stood an excellent chance of coming back during the new shuffle.
The main upshot of this wasn't a lot of chaos and back-and-forth policy churn. Rather, practical authority was concentrated to a large degree in the permanent bureacracy which made policy just beneath the high-level personnel turnover (the US, it's worth remembering, has an absurdly large number of political appointees in our cabinet agencies by European standards) and much of the country was basically run by very stable networks of bribery and extortion. Genuine instability is a phenomenon of the post-Tangentopoli era in which a huge wave of scandals destroyed all of the old system's major political parties and created the current dynamic where power alternates between a corrupt rightwing coalition and a hopelessly divided leftwing one.
--Matthew Yglesias