Voting is necessary civil engagement: but it is insufficient. Both parties agree on the two-party system. Both parties agree on first past the post voting. Both parties agree on taking money from "good" billionaires (i.e., legal bribery). Both parties agree on insider trading. Both parties agree on government bailouts. Both parties agree on proxy wars. And so on. In a two-party system, who do we vote for to address these issues?
Of course there are meaningful differences between the parties. But they use social issues (e.g., immigration) to divide the American people so they do not notice just how much both parties agree on. We need deeper systemic changes to this system that literally will never happen through voting.