Source 3: "The inducements will be so strong that it will be impossible to restrain our citizens from crossing the river… Thus our citizens will be removed to the immense distance of 2,000 to 3,000 miles from the capital of the Union, where they will scarcely ever feel the rays of general government; their affections will become alienated; they will gradually begin to view us as strangers." Senator Samuel White of Delaware Question 3: What is Senator White's prediction? How accurate was that prediction?

Lousiana was a former territory of Spain, which gave it to France with specific conditions. Conditions that according to Spain, France hadn't fulfilled, so Spain at any moment may make a strong case to regain that territory, so the U.S shouldn't touch that territory until the true ownership was clarified.
Louisiana was a vast and big territory with much cultural difference between them and the U.S and was too far from the capital, so all of this may make the Lousiana's citizens feel alienated from the other Americans and they would feel different and sooner or later they would declare independence from the U.S which would weaken the nation's position in the continent.

His prediction after the purchase was that they would lose the territory anyways because the Spanish may declare the French ownership invalid or because later the citizens of Lousiana would declare independence from the U.S.A. Obviously, his predications were totally wrong, since the purchase of Louisiana didn't give them just the opportunity to acquire that specific territory, but the position of the U.S became way more stronger since France was not in charge of any territory inside the continent; the Spanish position was very weakened, and finally gave the country access to the western territories that weren't guarded by the Spanish and later by Mexicans. The purchase of Lousiana was a very definitive moment in the growing phase of the United States.