I don't think anyone is suggesting replacing any form of government with another.
I think the point that was being made was that no system of government is perfect and immune from the type of corruption that exists in the states. Probably any government can descend into authoritarianism/fascism, if a particularly evil group of characters get power and those with the ability to stop them decide to do nothing. Every successful political system is successful in large part because politicians and the general electorate are not completely evil or stupid. The US is failing as a democracy not because their government design is inherently bad, but because of the people who are currently involved in government.