The phrase "a broader case for" is correct and usable in written English.
It can be used when discussing a more extensive argument or rationale supporting a particular idea or position.
Example: "The research presents a broader case for the importance of renewable energy in combating climate change."
Alternatives: "a wider argument for" or "a more extensive rationale for".
He acknowledged that the Knicks, who started the season 3-14, could not make a broader case for Lee's candidacy.
The passing of accounts charges accounting practitioners with the stewardship of silence and indicates a broader case for accounting theory to address the full continuum of accounting practices.
Instead, Mr. Kerry made a broader case for the secretary's ouster "for failure to do what he should have done" prosecuting the Iraq war.
We believe there is a broader case for membership way beyond the narrow terms of what the Prime Minister is asking for.
"Those campaigning for a 'remain' vote won't be trusted by undecided voters unless they acknowledge that reality and make a broader case for why being in this club makes free movement a price worth paying".
He used them to reiterate his call to roll back Bush administration tax breaks for oil companies and to make a broader case for his administration's accomplishments heading into an election season.
She also made a broad case for international cooperation.
Barack Obama today laid out a broad case for closing the Guantánamo Bay prison and banning the "enhanced interrogation techniques" that have been condemned as torture – while accusing his opponents of wanting to scare Americans to win political battles.
In an evening speech at the Palais des Beaux-Arts, Obama made a broad case for U.S. and European unity, for sanctions against Russia that could damage still-fragile European economies and for help leveraging American power that he made clear in this case does not include military force.
Although mild illness does not contribute substantially to disease burden, using a broader case definition for both the household survey and for the surveillance system might have captured more cases.
There's also a broader case to make for investing in Underscore.
