Over the long term I think anti-US democracies can be better than pro-US dictators. If a dictatorship is unresponsive to the population then a resistance too it will develop, if the US overtly supports the dictator this can have the effect of empowering the resistance since they can now cast the dictator as being a foreign lackey. This allows the resistance to cast their struggle in terms of us against the alien power and appeal to nationalistic instincts. If the resistance comes to power or gains significant influence a strongly anti-US policy will soon develop.