make a federal case (out) of (something)
To exaggerate or build up the importance of something; to make a big deal out of something. The phrase is often used to complain that someone is exaggerating a problem or alleged wrongdoing. So I ate your leftovers. Geez, don't make a federal case out of it! I'm not trying to make a federal case out of it, but I know you stole my new sweater!
make a federal case out of something
and make a big deal about somethingto exaggerate the seriousness of something. Come on. It was nothing! Don't make a federal case out of it. I only stepped on your toe. Don't make a big deal about it.