D. The Supreme Court outlawed malapportionment because it does not give each citizen an equal voice in government.
Malapportionment is the unequal distribution of voting power among voters or districts. In the case of the United States, it often refers to the unequal distribution of voters in legislative districts. The Supreme Court has ruled that such malapportionment is unconstitutional because it violates the principle of "one person, one vote" and does not give each citizen an equal voice in government. By outlawing malapportionment, the Court sought to ensure that each citizen's vote would have roughly equal weight and influence, regardless of where they live or which district they vote in.