A marginal district is one in which

• A. the winner in an election gets less than 55 percent of the vote
• B. voters frequently change party affiliation
• C. the constituency is made up largely of minority groups
• D. gerrymandering has produced a loose affiliation of interest groups

Answer: (A)

A marginal district is defined by its electoral competitiveness, where the winner does not secure a large share of the vote. When the winner has less than 55 percent, the race is considered tight enough that a relatively small shift in votes or turnout could change the outcome in the next election. This makes such districts highly contested and attractive targets for campaigns, since control of the seat could realistically flip.

The other ideas describe different concepts: voters who switch party affiliation speak to volatility in allegiance, not how close a race is; a district with a majority of minority residents relates to demographics, not competitiveness; and gerrymandering concerns how district lines are drawn to advantage parties, not the margin of victory in a single race.