What is the greatest obstacle to democracy and stable political systems in central america

The correct answer is - corruption.

Central America has been stuck in a very bad situation for quite some time now, and this is mainly because of the corrupt politicians that run the seven countries of this region. Everything in this countries functions on corruption, from people doing their daily activities, through people working in the public sector, to the politicians. This kind of damaging culture has developed over quite a long period, and seems to be just an ordinary thing, but it is actually destroying the region, and while most of the countries that are on the north and south from Central America are progressing, they are stuck in a vicious circle and don't seem to get out of it any time soon.