The USA’s strategic policy equates democracy with consumer capitalism, human rights, and economic and military stability. They are a set, for which ‘democracy” is a simply a shorthand. Which is unfortunate, since that brevity obscures the complexity of the strategy.
The USA spent the majority of the past century trying to prevent the alternative to consumer capitalism, world communism, from developing the military and economic power necessary to interfere with world oil production, and world trade – as well as preventing the further death and suffering that are the result of managed economies.
Therefore the simplistic statement “democracy is good”, means “Democracy that is good is democracy that advances consumer capitalism, will create states that are good world citizens and will not disrupt the world system of trade, and world production of oil.”
The problem that the USA has with islamic states, is that, having spent the past century trying to prevent the rise of anti-capitalist states, it appears that the muslim world is going to coalesce into three or so factions all of whom are militant and at least one of whom’s ambitions (Iran) is to control the price of oil as a means of concentrating the capital necessary to build a military strong enough to defeat the other two factions, thereby restoring the islamic empire.
So the USA is very cautious, and one should not confuse “democracy” which is simply the means of transitioning power, with the broader concept of democratic, consumer capitalism of small independent states all of whom are good world citizens. Those are different things.
Party politics is a nonsense-sport to entertain the population. The USA generally follows strategic policy, because the consequences are so serious, which is why all politicians, once in office, tend to follow it. If the world system of trade is dramatically threatened, the average american can lose a third to a half of his standard of living in far shorter order than we did in the great depression. And at the current level of social discord, the government may not be able to prevent civil conflict.