I've carried tubes w posters/prints on a number of domestic flights w/o issue; I'm a window seat addict, so it was a simple matter to put the tube "under" the seat in front of me but actually against the side wall (extending half way past my seat)
bubble-wrapped beverage items (wine, Scotch, Spanish olive oil, etc) further wrapped in a sweater or jacket in a checked bag survived our last two TATLs