Dual citizenship is a safety valve - a Plan B - in the event that the Land of The Free continues to shut down people’s freedoms. The US has already fallen to 15th or 16th on the list of Most Free Countries and if Hillary becomes President we will be falling even further.
It also represents competition between societies...if the country you are in disrespects it’s people, move elsewhere where liberty and the pursuit of happiness gets a better shot. When I can no longer stand living in California (which will be soon) I can move to Texas or Wyoming.
Similarly when the Gramski-ites, Alinsky-ites and the Globalists have completed their socialist transformation of the USA, I will be ready to move to country that affords me a higher level of freedom.
America is not a piece of real estate that I cling to - it is a fundamental idea that I cling to. If and when the idea is extinguished I will be ready to move on.