By "power erosion" I refer to the phenomenon which usually affects a party in power: the trust gets lower towards the end of the legal mandate, thus reducing the chances of wining the power for the next mandate.
In my native country, Romania, a much more fragile democracy (only 27 years after the fall of the Communism and a few years before WW2), I have seen several important political parties suffering from "power erosion":
- National Peasants' Party is almost 100 years old and failed to enter Parliament (5% electoral threshold) for three times in a row (the latest)
- National Liberal Party, more than 100 years old and one the most notorious parties in country's history got only 20% of total votes at the last elections and some analysts argue that they might get lower in lack of solutions
- Other smaller parties disappeared from the Parliament after 2-3 mandates
This article shows the evolution of public trust in Government:
The public’s trust in the federal government continues to be at historically low levels. Only 19% of Americans today say they can trust the government in Washington to do what is right “just about always” (3%) or “most of the time” (16%).
This article confirms the historical low trust level:
Public trust of government is near its all-time low according to the Pew Research Center, which finds a perfect storm of factors -- including a deep recession, high unemployment and polarized Congress -- are driving distrust near an all-time high of 80%.
At the same time, this table shows that the two main parties act and acted as a "political oligopoly" for many years.
Question: considering the low levels of public trust, how comes that there is virtually no political alternative to the two parties?