Image, Alex Borland
Amendment XXVIII, (proposed), Section 2:
"The United States and every State will enforce the right of a citizen eighteen years of age or older to vote, not to vote, or to abstain regarding any office or proposal, in United States or State elections.
Districts compete for funding.When a party's leaders are setting priorities and organizing coalitions voter turnout is one of the factors that gives a Representative bargaining power for their district. Even when it doesn't change the result of an election voter turnout of any kind, even abstention, makes a district's overall needs a higher priority to the party leadership, not something likely to be bargained away for very little.
Abstention has another, subtler effect. The larger the turnout, the less power imbalance and extremism can distort it. All the smaller factors that influence voters' preferences can only emerge enough to be meaningful when a very large percentage of the population votes, including those who abstain.
This amendment prohibits penalizing not voting (see No Penalty or Force).
You have a right to decide not to vote. Nonsuffrage due to error will be greatly reduced by states' compliance projects (see Making Elections Work). Voters will also be able to abstain instead of not voting. The Constitution doesn't prohibit abstention. It shows the public's level of confidence in the candidates, possibly making embarrassed candidates more responsive to the public's needs.
Canada recently introduced an abstention option and seems none the worse for it.