noun
power base (of a government)
Refers to the foundation of support that sustains a government or administration, including political backing, public approval, and institutional strength.
与党は地方組織を強化して政権基盤を固めようとしている。
The ruling party is trying to strengthen its power base by reinforcing local organizations.
支持率の低下が政権基盤を揺るがしている。
The decline in approval ratings is shaking the government's power base.
支持基盤 is a broader term for a support base, often used for individuals or organizations, while 政権基盤 specifically refers to the foundation of a government's power.
Compound of 政権 (political power) and 基盤 (foundation, base).