I thought it sort of reflected the United States' isolationist movement before it became actively involved in WWII.
The isolationist feelings among Americans prior to involvement in WWII was not based on racism (there is some serious irony in that sentence). In Terra Prime, humans wanted to stay away from aliens because of their fear, and distrust which led to hatred -- racism or, in this case, xenophobia.
Americans who wanted to avoid the WWII conflict simply wanted to stay out of what they perceived as "other people's war".
Both pre-WWII Americans and 24th century humans wanted to be "isolated" but the reasons for wanting isolation were entirely different between the two.