The phrase "a sizable constituency" is correct and usable in written English.
It can be used when referring to a significant or considerable group of supporters or members within a particular context, such as politics or community organizations.
Example: "The candidate has managed to build a sizable constituency that supports her policies and vision for the future."
Alternatives: "a large following" or "a significant base".
Is there a sizable constituency in America for completely privatizing local fire and police protection?
The movement is new, but there is a sizable constituency for it.
The easy answer is that Bernie Sanders came along and demonstrated that there's a sizable constituency for unabashed progressivism.
The Islamists dominated Egypt's first free elections after the ouster of President Hosni Mubarak and still represent a sizable constituency, especially outside the capital.
People affected by substance abuse are a sizable constituency in New Hampshire, and candidates have taken note.
Most of the labor rights activists were not there to support one specific candidate, but said they wanted to remind all of the candidates that income inequality and labor rights were central issues for a sizable constituency of voters here. .
Indeed, it's fair to wonder if all those polls showing young people are more open to socialism and suspicious of capitalism means any sizable constituency actually wants capital-S socialists, or just someone who can articulate the system's ills more sharply and convincingly than the rest.
Ms. Boyer, who is from Marseille, a city with a sizable Armenian constituency, denies playing politics.
Although her suburban Atlanta district is mostly black, Ms. McKinney has a sizable Jewish constituency, and Jewish voters here are alarmed by her support for Arab and Muslim causes.
Falun Gong founder Li Hongzhi has lived in the United States since 1996, and Falun Gong has a sizable global constituency.
Mr. Koch was believed to have no sizable constituency outside his East Side district, and Mr. Cuomo seemed to have no compelling identity.
