I read somewhere that Beagles trained for the Beagle Squad of the USDA are generally difficult to train but not possible. Trainers capitalize on the Beagle's one true weakness, and that is its appetite. The abundance of treats will certainly get your Beagle's full attention and make training much more easier.
Stubborn? Hmmm, intelligent and cunning. I swear my second beagle Katie would manipulate her puppy (ah, let me explain that her puppy was a golden retriever I got for her) so that the puppy would get in trouble for something Katie did, or she'd maneuver her so that she, Katie, could get what she wanted. It was incredible to sit back and watch her 'work'.
Stubborn? Hmmm.... does that include telling me off because she wanted to go for a walk and I didn't get to it quick enough? She did that once. She told me off all the way down the street. I was in hysterics almost.
Badger is stubborn. He likes to test his limits and see how much he will get away with first. As long as I correct him right away he is good. But yes they are very smart and they like to have their own way too!
Actually, that's more one of my current dogs, a shepherd/lab/heeler mix. She is ultra smart and ultra stubborn. Get this.
Dog: walks to crate and stares at it
Dog: gets in but then walks halfway out
Dog: backs up but two paws out
Dog: one paw in
Dog: finally in but stares
LOL However, there is an alternate version.
Me: Who wants a treat? Get in the Crate
Dog: inside crate, sitting down, and staring at me attentively in about 2 seconds.