I remember a ride on the Crescent back in 1990. No smoking, except in the lounge/cafe car. They had some kind of incredibly powerful HVAC system that seemed to be able to clear the smoke to the point that you couldn't even smell the smoke from a person puffing away across the table from you. But, of course, back then, the background reek from tobacco was much more common, so perhaps if I got into a time machine and was able to go back and ride in the same car, I would now notice the smell..
Oh, and in the "golden age" before Amtrak, most railroads allowed smoking in special "smoking cars." These reeked of tobacco, even if no one was smoking, and, except for the smokers, nobody wanted to ride in them. I found that out the hard way on one of my early joyrides, when I found an almost empty car on a crowded PRR NEC train. I didn't take me long to figure out why that car was empty.
Just to round out the tales of the past, back when I was in college, I smoked a pipe, and would you believe it, but TWA allowed my to smoke my pipe on an
airplane in flight! In retrospect, I'm surprised the other passengers didn't pitch me out the door without a parachute!
In sort, No, No, NO, never allow smoking on the train again. If necessary, they should have nicotine gum for sale in the cafe car.