Unitarian Universalists covenent together to affirm and support seven princples the fifth of which is the right of conscience and the use of the democratic process within our congregations and in society at large.
So, the correct answer is "yes." It is not only your civic duty to vote, it is part of our religious covenant as well.
One of the more significant social injustices perpetrated throughout U.S. history has been voter suppression. It has been especially virulent and malicious in the last 40 years. Disenfranchising large segments of what the political party in control considers to be undersirable voters has led to systemic, institutional injustices throughout the country. Therefore, it is encumbent on UUs not only to vote themselves but to encourage others to vote as well. This encourgement of others to vote is based on UUs second principle which is justice, equity, and compassion in human relations.
Here is a video giving a good overview of the mid-terms which comes, interestingly, from Australia.
Vote on this coming Tuesday, November 6, 2018.