What was a primary obstacle to worker unity in the 1880s

The main obstacle was the political discrepancy between the large number of immigrants.

Explanation:

Unity in the 1880s included a large number of immigrants, including Italians, Irish and Jews. Because of the precarious situation and disadvantages for these immigrants, each of them eventually adopted opposing philosophies and political strands. Each immigrant joined the political side that they believed would be of greater help to their people, so the Italians decided to adopt republican ideologies, while the Irish and Jews decided to adopt democratic ideologies. This generated a major political discrepancy and eventually led to strife among the members of unity, which eventually weakened and had no goal followed by all.