Of course, it is always worrying to know that there is no active opposition to monitor the government's actions. This goes against even the most basic definition of what a democracy is, of course.
That being said, we cannot forget that the opposition boycotted the election in Venezuela, for one, which greatly decreased the number of opposition members in government. On the other hand, this worrying situation—namely that a national party is attempting to be the sole representative on the political scene, which is bad for a true democracy and true debate—reflects a trend whereby power is becoming increasingly centralized, especially the executive power, nationally and elsewhere in Latin America, as well.
In other words, this trend unfortunately does not wear any political colours, which is what I was trying to say. The centralization of power by the national executive is a phenomenon which is taking place in Venezuela, as well as in other countries in that part of the world that are not necessarily moving to the left, as some people claim the trend has been, starting in 2000.