The reason that political establishments have always been biased against monetary deflation can be found in the manner in which wealth transfer occurs under inflationary and deflationary environments.

During an inflationary credit expansion, wealth is transferred from the public in general to the earliest recipients of the newly created credit money. In practice, the earliest recipients are interest groups with the strongest political connections to the state and, in particular, the state institutions that control monetary policy (i.e., the Federal Reserve in the United States). Importantly, the wealth transfer that takes place during an inflation is hidden and largely unrecognized by the majority of the population. The population is unaware that the supply of money is increasing and the attendant rise in prices, ostensibly beneficial to business, initially

"produces [a] general state of euphoria, a false sense of wellbeing, in which everybody seems to prosper. Those who without inflation would have made high profits make still higher ones. Those who would have made normal profits make unusually high ones. And not only businesses which were near failure but even some which ought to fail are kept above water by the unexpected boom. There is a general excess of demand over supply — all is saleable and everybody can continue what he had been doing."
In an inflationary environment, wealth transfer proceeds insidiously and is masked by a perceived prosperity. The unmasking finally occurs at the end of the credit boom when the market's tendency to clear prior losses takes hold. Failed businesses are liquidated and their capital is transferred, usually through bankruptcy, to creditors who must acknowledge losses on these misguided investments. Unemployment soars and social unrest replaces the former sense of euphoria attending the credit boom. Professor Hülsmann summarizes the differences between the transfers of wealth occurring under inflation and deflation as such:

"In short, the true crux of deflation is that it does not hide the redistribution going hand in hand with changes in the quantity of money. It entails visible misery for many people, to the benefit of equally visible winners. This starkly contrasts with inflation, which creates anonymous winners at the expense of anonymous losers. …
[Inflation] is a secret rip-off and thus the perfect vehicle for the exploitation of a population through its (false) elites, whereas deflation means open redistribution through bankruptcy according to the law."

And here lies the answer to why the state prefers a policy of controlled inflation. Only in an inflationary environment can state largesse be conferred to the politically well-connected without raising public ire. The widespread and visible transfers of property through bankruptcy that must take place during a deflation are often politically destabilizing and thus highly unappealing to any regime. A sense of injustice grows within the population as banks are saved from the folly of their misguided investments with taxpayer-funded bailouts, while debtors with no political clout have property seized in bankruptcy.

* http://mises.org/daily/4974/The-Politics-of-Deflation