noun
party strength; political influence of a party
Refers to the overall power, influence, or momentum of a political party, often in terms of membership, electoral performance, or public support. Common in news reporting.
選挙の結果、党勢が拡大した。
As a result of the election, the party's strength expanded.
党勢の衰退が明らかになっ
The decline of the party's influence became clear.