Why politicians don't like electoral change

Ever wonder why it seems so difficult to get any change in our political system? Here is part of a very interesting citation by

Professors Karp, Bowler & Donovan. The full citation is posted here link text(Why Politicians Like Electoral Institutions)

Our answer to that question is that winners become invested in, or at least attached to, the rules that made them winners. Winners are committed to the status quo—even if they are very recent winners and even if they are in the opposition. This is a somewhat different interpretation of why institutions represent “congealed preferences” than offered by Riker,to whom we owe the phrase.Winners are reluctant to
change rules that made them winners and—hence— we can expect to see only very slow changes in those sorts of rules. We know that the people and parties who form governments change relatively frequently. But we also know that the electoral institutions that structure how these governments come into place are quite static.Much of the stability of election rules may reflect that being in parliament (winning) quickly unites actors who differ in terms of policy preferences
and ideology at least on one dimension. Winning election and serving in parliament leads to a unifying electoral self-interest that dampens support for institutional
change among those who may have embraced change when on the outside looking in.