The phrase "a vast segment of" is correct and usable in written English.
It can be used to refer to a large portion or part of a particular group, population, or category.
Example: "A vast segment of the population supports the new policy, indicating a significant shift in public opinion."
Alternatives: "a large portion of" or "a significant part of".
But their bureaucratic task is but one example of the demands for fees and paperwork with which Dodd-Frank will blanket a vast segment of America's economy.
After a century of dependence on a single agricultural commodity, Yucatan is now scrambling to rescue a vast segment of its population from economic lassitude by fostering new sources of income.
That made sense 75 years ago, when a relatively small number of corporations — oil and coal companies, steel producers, car makers — controlled a vast segment of the work force and when government was a comparatively anemic enterprise.
Gillibrand and Warren in particular have made their experiences as mothers defining themes in the first few weeks of their campaigns, working to connect with a vast segment of voters and push for policies like paid leave, affordable child care and universal pre-k.
The self-government advocated, then, is one based on the premise that a white male property-owner minority should be able to deny the humanity of a vast segment of the population as well as deny them any rights whatsoever in order to perpetuate the institution of bond-slavery.
A vast segment of We the People just want to begin spending time at work, and then breathe a sigh of relief when a steady paycheck arrives again.
Is the vast segment of so-called popular literature merely a product of the "culture industry," or could kitsch, for example, be understood as something more subversive?
It might be an idea to ask the networks to tell it to Hanoi — what if the networks were set as the sounding board for the vast segment of American people who support the President and his peace efforts.
The economic collapse has taken a toll on vast segments of society, but it has affected some groups disproportionately.
The Senate race — the third since 2010 — had only seemed to highlight a sense of voter fatigue, with vast segments of the public undecided and analysts predicting a low voter turnout in the Senate primaries on April 30.
This is an encouraging sign, which indicates that vast segments of American society do not support Trump's agenda.
