It is possible for Dual Citizens to become Good Americans because people who adopt these roles realize the seriousness of having two motherlands. They pledge to adhere to the rules of each country lawfully. In addition, dual citizens rarely share this status with two enemy countries. In most cases there is no conflict at all, and in many cases cohesion in ethical and moral principles of the laws of each country.
Americans who hold citizenship in the United States and another country are the same as any other Americans. They have the ability to become productive members of society and contribute to the United States. In fact, some may live here all of the time, such as a child whose parents are from another country but who is born in the United States. Each person is a unique individual, with the capabilities of being a good citizen.
In most cases, dual citizens of one country and then the United States can become great Americans. These individuals contribute to society with their skills and talents in various ways. It's not right to assume that people with citizenship in another country won't contribute to being an American in one way or another.
I believe there are too many tax loop holes for people with a dual citizenship with the United States and another country. I believe these people could become good Americans, but I think if they live in this country, then they should pay their fair share of taxes, just like the rest of us.
Being a dual citizen doesn't make one un-American. The fact that America allows dual citizenship is what makes American identity so fluid. Those who want to whitewash this idea want America to be a singularly ethnic state, but it's not. People should be allowed to be American and also belong to their original country.
It also depends on the individual. If the person is proud of his or her heritage that person will never be a true America. They will be American in name only. However immigrants from Western Countries would not have an issue integrating into American culture. However individuals and I say it as an immigrant from South America, Latin American immigrants have a very big grey area. Too many are very proud of their countries of origin even though they were places they fled to survie and seek to replicate and spread their culture of origin as illogical as it may sound.
So in the end, immigrants from Western Civilization have no trouble integrating into any other country, for the most part. However immigrants from Asia and Latin America have a tendency to go into neighborhoods specifically for them which not only delays their learning of the English language but also turns bigger and bigger swaths of the city into replicas of their former home. Reducing standard of living, their own economic prosperity.
We have to acknowledge the fact that not all immigrants share the same adaptable culture, and not all cultures are as efficient.
So in the end to answer plainly, no a dual citizen cannot become good Americans BUT that depends on their culture of origin. If we are speaking about an American with British/German/Australian/Austrian/French/Spaniard/Irish/Scottish/Israeli etc etc citizenship they are for the most part respectful and adaptable.
However I came from Colombia, and I can testify that a large percentage of latin American immigrants are respectful but aren't adaptable. The latter is because they are still staunchly loyal and proud of their culture of origin. It doesn't make a lot of sense to run away from Colombia/Mexico etc to move to the US while believing Mexican/Colombia/Guatemalan culture is something to be proud of, something to pass on and something to spread.
It depends on the culture of origin, western culture immigrants have little problem, personally I can say latin american immigrants have a wide grey area where it could swing both ways. If you do not believe me, watch the drop out rate, the crime rate, the poverty rate rise when too many hispanic immigrants congregate into a self sufficient culture group.
The best way to ensure double citizenship of non western immigrants isn't an issue regarding taxes and loyalty is to have limited immigration. Given Western Countries are moving into the information age, the time for a mass of uneducated unskilled and barely literate immigrant group is a liability rather than a strength. By limiting immigration i.E: Accepting 100k immigrants from 4 culture groups is different than accepting, 100k immigrants from a single culture group. The former, doesn't allow immigrants to provide culture support to one another, and thus stops their original culture from spreading. It pushes them to identify with this country first rather than with a replica of their own created within the US.