Here's some basic info on what would happen, including on which Senators to eye as potential swing-votes on both parties.
There's a section in the book "Freakonomics" that uses data to postulate that legalization of abortion leads to a drop in crime rates. Levitt uses mountains of data to support the idea, and it hits very close to my belief that society benefits from being one in which every child is a wanted child.
It's not going to be as dire as people think. First, the culture of the United States has changed A LOT since 1973. Second, morning after and abortion pills are now on the market that eliminate the need to actually go to a clinic. Third, there will be states on the West Coast, East Coast and Upper Midwest that protect abortion rights (so, regardless of where you live, you will be able to travel to a clinic), and Fourth, in States like Florida, North Carolina and Virginia it is going to be very, very difficult for lawmakers to go back to 1960's era laws. Yes, the Conservatives have won the Supreme Court, but Liberals have won the culture war.