He's '(as) stubborn as a mule'. [=he's very/extremely stubborn]
She 'has a stubborn streak'. [=she is often stubborn]
She's wrong, but she's too 'stubborn' to admit it.
(..) You're... you're... you're tough... and, uh... and persistent and decisive. Mm. Kind of sounds like you're calling me stubborn. Yeah, well... you are insanely stubborn and... Mm-hmm. Yeah. - A little domineering... - Uh-huh. (..)2017 TvShow: Superstore Title: Cheyenne's Wedding Season: 2 Episode 20