Manifest Destiny was a distinctly racist concept in the first place. The idea was that white man was destined to conquer the west and this meant subduing anyone else who happened to live there. White man alone was entitled to this "destiny". It used the ideas of Jacksonian democracy of a "white man's democracy" to develop these beliefs.
Cultural exchange and the change in global population are the immediate consequences of the columbian exchange. Proliferation of invasive species and some communicable diseases are the most important byproducts of the columbian exchange.
A dissenting opinion disagrees with the majority because of the reasoning and/or the principles of law on which the decision is based. A concurring opinion agrees with the end result of the court but offers further comment possibly because they disagree with how the court reached its conclusion.
