Really? What makes you say that?
Prior to Roe v Wade in 1973, only four states allowed abortions (Alaska, Hawaii, New York, and Washington). Prior to 1967, no state allowed it.
It could happen that, if 5 or 6 states allowed abortion, the remaining states would feel free to ban it, figuring that its citizens could go to one of the "legal' states.
I don't think it's possible to turn back the clock. We have a whole generation of adults born since then who have always heard that they have a constitutional right to an abortion. As time passes, the proportion of the population with that perception will obviously increase.
In the abstract, everyone is opposed to giving up constitutional rights, so it's a tough battle. I think you can forget ever having abortion banned in the blue states, and in many of the red states it would also be difficult to enact them.
All this presumes that the Supreme Court would overturn Roe, something which is no slam dunk. But, at a minimum, I think it's safe to predict that abortion will be legal in more places in this country than in 1973 for the rest of our lives, no matter what.