Over at Flopping Aces, we see the idiom being used and misunderstood.
Hume’s comment was, “It’s hard to swing a cat in Congress without hitting someone who is running for President.” I had an image of Brit grabbing Felix the cat fresh from a commercial, picking him up by the tail, and while the cat hissed, screamed, and clawed like mad, I envisioned the stinging furball getting smacked into the faces of different Presidential candidates. I had to laugh, but it was when I tried to imagine the sound that I really lost it. All I can say is Maker’s Mark hurts when it goes through your nose.The expression doesn't refer to a real live breathing cat.
We're talking about the cat o' nine tails, a flogging device used in the British Navy to administer punishment. It was a short handled device with mulitiple lashes. Those lashes were sometimes tipped with knots, or lead balls. The device was swung, applying the lash to the back of the miscreant. It was not a pleasant punishment.
If you didn't have room to swing a cat, you were in a small room. If you couldn't swing a cat without hitting other people, the room was plainly crowded.
As interesting as it is to envision a person swinging a screetching feline, the idiom describes something else entirely.
I thought I'd clear that up.