The phrase "expand the influence of" is correct and usable in written English.
You can use it when discussing efforts to increase the power, reach, or impact of a person, organization, or idea.
Example: "The organization aims to expand the influence of sustainable practices in the community."
Alternatives: "broaden the impact of" or "increase the reach of".
While most incoming vice presidents arrive eager to expand the influence of the office, Mr. Biden faces the unusual conundrum of figuring out how to scale it back.
The bid, if successful, would significantly expand the influence of Électricité de France, the French national utility, south of the Alps.
Other countries are already trying to expand the influence of their legal rules or to fight off the influence of America's legal system.
The injection of new capital from CME comes as the exchange is aiming to expand the influence of the Oman crude oil futures contract.
The chairman and chief executive of the Financial Industry Regulatory Authority has ambitious plans to expand the influence of Wall Street's self-regulatory agency.
Mr. Karzai's comments come in the wake of news reports about an American military review of Afghanistan that says poppy cultivation and opium production will increase and expand the influence of drug magnates at all levels of the government.
And as the Union expands, the influence of members like France, Germany and the Netherlands becomes more diluted.
The amendments also included measures that expanded the influence of the president and parliament over judicial appointments.
The use of sires proved in this way together with artificial insemination has enabled dairymen to improve their herds by greatly expanding the influence of genetically superior bulls.
M.I.T. said the decision to turn over management of the program to the Indian government did not represent an end to the university's interest in expanding the influence of the Media Lab by building outposts in other countries.
