Not to mention, though I will, that Mexico is only one of the countries in "America" on the North America tectonic plate. Gulf of America, therefore, is actually more descriptive, and a more "inclusive", name than "Gulf of Mexico" was. Trump didn't rename the body of water, "Gulf of the United States", he renamed in "Gulf of America".
You'd think that the collectivists, who love to rename things and redefine terms, would be all on board with taking the name that resulted from colonialism and making it a generic, all encompassing, one instead . . . but you would have to forget about TDS playing such a critical role in their ideology, and the underlying hypocrisy surrounding much of their ideology, before that thought could take root.