The NTSB makes recommendations, but it's up to the states. What the states do may affect Federal grant money.
Which means it's really not up to the states. Kind of like back in the 80's when the feds said you can keep the drinking age at 18, but if you don't raise it to 21, then we cut you off of federal highway dollars. A choice that's not really a choice.
I think people shouldn't text while driving, and I think people should wear helmets, but I don't think there should be a law. We have laws against the things that result from texting while driving, like leaving your lane, causing accidents, etc. We also have laws against speeding, driving drunk, illegal racing, etc., and it doesn't stop those things.
I also have a problem with the stats used. They say distracted driving is the # cause of accidents. I have no doubt, but they imply it's mostly due to talking on the phone. If I am driving and I see a pretty girl on the sidewalk and run into the car in front of me, that's distracted driving. If I'm talking to the person in the car and glance over to them, and hit another car, that's distracted driving, as is fiddling with the radio, etc. My guess is that 'distracted driving' has been the #1 cause of accidents since cars were invented. And even if they ban cell phone use in cars, it will still be the #1 cause.
There's a car commercial floating around where they advertise a feature where the car can read you your texts. The kid driving gets a text and he looks up and there's a cop on a motorcycle on either side of him and he kind of slinks down into his seat until the car starts reading him his text. Whole thing kind of gives me the creeps.