"national case" is a correct and usable phrase in written English.
You could use it to refer to a legal case or issue with national significance. For example, "The Supreme Court will review the national case about gun legislation."
"There's always pressure as a prosecutor to win, but it's a national case".
Now, a dispute between the two over a crucial match Sunday has spilled into politics and become a national case.
Partly, too, it was our diminishing sense of history, our national case of intellectual attention deficit disorder.
You're in essence a local prosecutor writ large, and you're taking on what amounts to a national case, a national industry.
But by taking advantage of the powerful New York state securities law known as the Martin Act, Mr. Schneiderman has turned it into a national case.
Mr. Giuliani said Chicago's experience has served as a national case study for how to turn around a failing school district.
S.& P. also released on Tuesday the national Case-Shiller index, which covers a sample of homes across the country, including rural areas and smaller cities.
To report national case-finding results for nontuberculous mycobacterial keratitis and describe its association with laser in situ keratomileusis (LASIK).
Rubella surveillance in Kenya is integrated within the national case-based measles surveillance system.
During this outbreak, a relatively high national case-fatality ratio (CFR) of 3.2% was recorded.
Our national case-control study addressed a large number of environmental factors potentially involved in the etiology of RA.
