Final answer:
Party eras, critical elections, and party realignment are terms used in U.S. politics to describe distinctive periods of change in the party system, shifts in voter allegiances, and long-term changes in party coalitions and ideology.
Step-by-step explanation:
In U.S. history, party eras refer to distinctive periods when new political parties emerged, control of the presidency shifted, or significant changes occurred within a party's makeup. These party eras signify changes in party loyalties among the electorate.
Critical elections represent sudden, clear, and long-term shifts in voter allegiances. They result in a realignment of party loyalties. For example, the 1932 election, won by Franklin D. Roosevelt, was a critical election that led to a realignment where the Democratic Party dominated for several presidential elections.
Party realignment occurs when there is a significant and lasting change in the political landscape, including changes in party coalitions, voter preferences, and party ideology. It often follows a critical election and can lead to a shift in party dominance and policies.