I just don't know how well founded this idea is Casper, besides what people have told you. Yes, it's in the wildlife code (as Matt pointed out he had to dig through), but that is not what enforcement is enforcing. That's what the legislature put together (which didn't they just make it legal to eat road kill?

).
TWRA is enforcing the fishing regulations. And that's what you're doing. Collecting bait on a fishing liscence.
2007 Tennessee Fishing Regulations
PG 25
A legal minnow trap shall not have a mouth opening or openings that exceeds 1-1/2 inches in diameter. A minnow seine is a net having mesh size no greater than three-eights inch on the square and no longer than 10 feet.
And then a whole bunch of stuff about Cannon, Lincoln, Macon, Moore, Smith, Sumner and Trousdale counties, along with the stoneroller clause for Carter, Unicoi, Washington, Johnson, Morgan and Sullivan Counties (which does anyone know the history of this?)
PG 26
It is illegal to take any fish or turtle that is endangerd, threatened or listed as in need of management.
There is no specification on the genera of what makes a "bait fish" aside from contrasting that with "sport fish", which are any species that have a legal definition in the fishing regulations (size, creel limit, etc).
If you're following this, I don't know how anyone has a leg to stand on to give you a ticket that's going to stick.
If they decide to make a law like Illinois that defines "Bait as minnows and round bodied suckers", then fine. No more darters from TN. But until then, you are as within the law as possible.
Again, we got into trouble in Kentucky because 1) We had big nets that we were blockade seining (it LOOKED like we were poaching!) and 2) we made let people who were in the know make the assumption that we would be okay on the TVA Biologists Permit who was finishing the survey on the Big South Fork. If we'd be using regular sized seines, and we'd all offered fishing liscences, that woulda been a whole different 2 hours my friend.
Btw, I finally got the pictures back from our NC run in

And that was 1) an oversight on our part for being in a state park, which required an additional permit and 2) we TOLD them we were going to be there! lol
No more permits and oversized seines for me man, unless I have agency people there with me. It ain't worth the hassle.
Todd