Ethnic minorities are fighting against prejudice, poverty, and oppression.

Literal

Ethnic-minorities [topic-は] prejudice, poverty, oppression [against-と] are-fighting.

The particle と paired with 戦う marks the opponent — 'fight against X,' not 'fight together with X.' Whether と means 'with' or 'against' depends on the verb's semantics. Note how the listed nouns 偏見、貧困、抑圧 attach と only to the final item, the standard pattern for Japanese enumerations.