Defining colonialism is not about whether or not people like their situation or whether or not it is the worst or the best situation, it is instead a simple matter of stating what level of self-determination or sovereignty self-government a community has.
It is a category which indicates that a community, a polity exists in a fundamentally unequal relationship with another. Where one community holds a gross amount of power over another and there is an absence of any formal and uncoerced acceptance of that situation that is colonialism.
It doesn't have to be brutal or nasty, it can be banal and naturalized, and in fact that it is precisely what every colonizer wants, to hold excessive power over a place from which their restrictions or limitations pale in comparison.
To have a place where your control which does not make any rational or moral sense over the land or the people there is justified.
One of the main ways in which you can perceive Guam's colonial status today is through the Insular Cases and much Federal-Territorial case law which has developed over the years.
The initial decisions of the Insular Cases which argued that the territories of the United States have no inherent rights other than that which the US Congress gives them continue to be the law of the land for the US as of today.
The Insular Cases has an interesting way of expressing the most basic way of perceiving colonialism. The Insular Cases do not argue that the people of the territories should be treated well, and neither do they argue that the people in the territories should be treated like crap.
What they fundamentally argue is that it is not up to the people of the territories what happens to them, but the Federal Government of the United States.
It is the choice of the Federales what they want to do. If they want to treat the people of the territories like they are regular garden-variety Americans, they can do that.
If they want to segregate them or treat them differently they can.
One of the things which makes this muddier now is the fact that people who are from the territories with the exception of American Samoa are US citizens, and so there remains an unresolved issue of whether or not this absolute authority extends to both the land and the people or only the land.
What we do know is that in terms of fixing Guam's colonial status, meaning the island finally undergoing a process of decolonization, Presidents and Cabinets and Congresses for decades have been very clear in how they would "allow" this to happen.
That although territories are not fully within the circle of American political belonging, this exceptionalism is not supposed to afford them any extra rights, not even in terms of their decolonizing.
This is where we can see colonialism in the way it usually appears in Guam's case, as a stupid joke. Guam is allowed to decolonize so long as it always remains within the authority over the colonizer, it is not allowed to decolonize in anyway which extends beyond what the colonizer wants or is willing to allow.
This is of course hypocritical, immoral, wrong and all of those things and in the case of Guam all of the nice things or great feelings of Americaness that people feel do nothing to affect this simple fact.
Guam is a colony and it will remain so until this is changed, and making excuses that colonialism doesn't exist or is somehow the best thing for Guam doesn't do much except implicitly articulate that Guam is one of those unique places in the world which should not have any control over its future.