I think his stimulus vote might have been the proverbial straw that broke the camel's back.
I dont know about that. The majority of Democrats in this district are likely Dixiecrats that generally support Boyd's vote against the stimulus.
Travis Childers, Jim Marshall, Lincoln Davis and many other Democrats are in districts full of Dixiecrats but voted for the bill. And so did the majority of Blue Dogs.
And Boyd is an entrenched incumbent who hasn't much to worry about his reelection, unlike some other No votes (Bright, Kratovil, Minnick).