Answer: a responsibility that is central to our system of government.
Step-by-step explanation:
Because President Franklin D. Roosevelt mentions that the vote is the central principle of the American Constitutional system and any citizen of the nation that has the right to register to vote has also the obligation (responsibility) to actually go and vote, this is regardless of which party it comes from and to ensure that the individual is able to express support or preference for a certain motion, proposal, candidate, or selection of candidates during the act of voting.