The act of voting has an opportunity cost.
It takes time and effort to stand in long queues, when many other valuable things could be done in the same period of time. It requires plenty of research and adequate information about the candidates to decide who to vote for.
To say that voting is a moral obligation for everyone living in a democracy, just because it is a key ingredient in democracy, is absurd. Nobody should compel someone to come out and vote if the latter does not intend to cast his vote for none of the candidates.
The concept of voting as a moral obligation stems from the fact that every vote counts and it has the potential to tilt the favor of the final outcome.
Additionally, some theorists believe that the act of voting, gives a thumbs up to the power and progress of democracy: a right not achieved or obtained in a system of government which is despotically dictator-based or monarchical.
This theory comes from a couple of basic concepts: the simple concept of “Instrumental Vote”, where a person goes out to vote for a probable winnable candidate.
Another reason to vote is to change the mandate.
A candidate, always needs to win an election at any level by a certain majority to enable himself to pursue his directives. In case of a closely-predicted-election, people tend to vote in a manner so that their candidate gets the required mandate to pursue their policies.
Though nobody can know the exact marginal effectiveness of any candidate, they vote to give their preferred candidate the required mandate, and in a way, make their vote instrumental.
Finally, many people vote for a cause.
That is the most common reason to vote. Expectations from a candidate or a representative, to work on certain issues, are predominantly the key factor to vote in elections or polls.
Candidates who are characterized by affable qualities often tend to create a visceral connection with their voters. Not only that, some of them raise issues which are never brought to the mainstream and because of these reasons, people find a moral obligation to vote for the candidate.
But regardless of the aforementioned reasons, no one is objectively bound in any democracy to vote out of an obligation. Voting is subjective.
Individual principles and beliefs do matter.
It is entirely possible that the candidates in the election run do not sufficiently convince some citizens to vote for either candidate.
Whether that is due to candidates’ backgrounds, lack of door-to-door campaigning or polar-opposite beliefs, the decision to vote or not vote is voluntary.
Nobody gets to police someone’s values or principles and make it compulsive for them to betray their individual beliefs and vote for someone whom they have no affinity for.
Some ideas between a candidate and a voter will definitely match, but whether it will subjectively convince him to vote for that candidate lies with the very voter himself.
Another concept which borders on the same vein is that sometimes, it is our moral obligation to vote for the lesser of the two evils. The underlying importance of this, as held by many theorists, is to reduce the graver injustice, which might presumably be caused by the greater of the two evils.
But regardless, when democracy offers freedom of speech, freedom of religion and freedom of choice and expression, it is incredibly incongruous on the part of some theorists to take a dig at someone’s freedom of choice and objectively proclaim, vote for the lesser of the two evils.
Now for some readers’ sake, freedom of choice in voting should not be confused with bargaining for a particular salary at work, where there is a consensual relationship between the employer and the employee. In that case, you have to make some compromise, just because it is a deal.
Voting is not a deal, it is a form of support or lack of support for a candidate, which remains up to individuals.
There is a concept of moral vote, where it lies with the morality of the voter to decide whom they would give the vote and whether there would vote or not.
Sometimes, people are within their rights to refrain themselves to not go out and vote for any candidate and nobody has any right to question their motive.
It’s always voluntary and subjective.