In plurality voting, which statement is most accurate about its typical effect on party systems?

• A. It often yields two-party systems and under-representation of minor parties.
• B. It guarantees a majority winner in every district.
• C. It prevents third parties from running.
• D. It yields proportional representation.

Answer: (D)

In plurality (first-past-the-post) voting in single-member districts, the candidate with the most votes wins, even if that winner doesn't have a majority. This structure creates strong incentives for voters to converge around two major parties: voters worry about “wasting” votes on a party unlikely to win, so they shift support to one of the two leading parties to ensure their vote helps elect someone. Over time, this strategic behavior, plus the winner-takes-all seat, tends to push the party system toward two dominant parties and leaves minor parties underrepresented in the legislature relative to their share of public support.

That’s why the typical effect is a two-party system with under-representation of minor parties. The other statements don’t fit this pattern: a district can be won without a majority, third parties can still run (but rarely win seats), and plurality fails to produce proportional representation, which is more characteristic of proportional systems.