> but also wonder, what would be the problem with people deciding it is illegal in some states, and illegal in others?

In practical terms, we're already seeing problems with state governments getting into beefs with one another. Some states which have outlawed abortion are attempting to make it a crime to go to another state to obtain one. California is running ads in Florida telling residents to move to California to preserve their rights, but California has a housing crisis so severe that people literally cannot afford to move to California.

Like imagine the issues that would come up if Poland was attempting to restrict freedom of movement of women traveling to Germany for an abortion, while Germany is running TV/radio ads in Poland encouraging people and businesses to move to Germany.

All these interstate arguments are supposed to be the domain of the federal government, but states which have outlawed abortion believe the supreme court will side with them and keep the federal government off their backs. Nobody is foolish enough to believe this decision is solely about the constitutionality of abortion bans. Conservative states recognize that the supreme court will now side with them no matter what.

But philosophically, the problem is that abortion (and privacy) is a fundamental human right, and these rights are being denied to Americans. The US is not the EU. We're not Ohioans and Texans and Californians like EU citizens are French, and Germans, and Poles. We are all Americans. We fought a war and then passed the 14th amendment partially on this basis. Individual rights for American should be available to all Americans, no matter what state they reside in.

> What's holding people back from voting, or moving to another state which more closely matches their politician views?

> Similar to the EU it is low friction to move state, right? When plenty of people apparently oppose abortion, why not let them..

It's not that simple for a number of reasons. The simplest is that minors aren't allowed to move on their own, barring certain exceptions, but they can get pregnant. Even after people reach the age of majority (18 in the US), because of the way our economy and health insurance systems evolved, people can be dependent on their parents for shelter and healthcare well into their mid-20s.

But the bigger problem is that the US is a very large but sparsely-populated country. in the most extreme example, Wyoming is a state the size of the UK, but has a population of less than 600,000. The states that outlaw abortion tend to be more sparsely populated, but still cover roughly half of the population, simply because there are so many of them. West coast states are also fairly sparsely populated, but partially because so much of the land is owned from the federal government, and the population centers are crowded near the coast.

If say, 20% of the total US population wanted to move from states that have outlawed abortion to states that haven't, that's a huge migration, and there isn't enough housing available. The US has been building less housing than we need for natural population growth since the 2008 crash.

And, to be fair, a small amount of that population growth in liberal states has been from people fleeing conservative states. But even in the most liberal states, so much of our economy is based around stable/rising real estate prices, which prevents building new housing at the rate that we need it. We're totally unprepared for citizens fleeing states where abortion is illegal.

EDIT: In case it wasn't obvious from the above, many people residing in states where abortion is now illegal cannot afford to move. It would be like asking the average citizen in rural Poland to move to Zurich.