While there are many other proposals, that kind of tax policy change would, in itself, definitely be a big change. I encourage people to use this calculator to determine your effective tax rate at various times in the past. If your family is like mine, reverting to the tax policy of the 60s and 70s would be a very large hit to us every year.
The things that made America so wealthy were changed pre-2000. It takes time for those changes to really impact society, and for people to realize it. And no one really talking about "fundamental" change. They're talking about raising taxes back to what they used to be like in the 60s and 70s. Not just in terms of the rate, but the percentage of the tax burden that falls on each segment of society.