Now that Roe vs. Wade is expected to be overturned, many politicians are calling for legislation to protect the right to an abortion to be passed on the federal level. But on what grounds could the federal government legalize abortions in all 50 states? Would they be forced to open federal "abortion clinics" to prevent state jurisdiction? Are there similar precedents of the Federal government legalizing something against the wishes of the states?
The federal government has the power to regulate interstate commerce, and the current definition is incredibly broad -- certainly broad enough to include the provision of abortions.
If it were challenged, the government would likely rely on Gonzales v. Raich, 545 U.S. 1 (2005). In Gonzales, two patients who used medical marijuana as authorized by state law challenged the federal government's laws prohibiting the use of medical marijuana. They argued that because they were growing their own marijuana, because it never left the state, and because it was for personal, noncommercial use, it was outside Congress' authority to regulate interstate commerce. But the Supreme Court rejected their arguments, holding that Congress could use its Commerce Clause authority to enact health-care laws regulating access to marijuana and pre-empt contradictory state health-care laws.
The federal government's case for regulating abortions would be event stronger than its case in Gonzales: First, because obtaining an abortion is typically a commercial enterprise; it is likely covered by insurance, and even if it patient isn't charged, someone is likely paying the doctor money to perform it. Also, abortions more obviously implicate interstate commerce because patients frequently travel from state to another to obtain one, because clinics order supplies and services from outside the state, and because they rely on instrumentalities of interstate commerce (highways, telephone lines, the Internet) to do their job.
Indeed, as far as I know, every court to consider the issue has concluded that regulating access to abortion is a straightforward application of the Commerce Clause. See, e.g., Terry v. Reno, 101 F.3d 1412, 1418 (D.C. Cir. 1996) (“Violent and obstructive activity outside abortion clinics adversely affects interstate commerce in reproductive health services. In enacting the Access Act, Congress did not exceed its Commerce Clause power.”); Cheffer v. Reno, 55 F.3d 1517, 1520-21 (11th Cir. 1995) (“Congress found that doctors and patients often travel across state lines to provide and receive services, id.; in other words, there is an interstate market both with respect to patients and doctors. In addition, the clinics receive supplies through interstate commerce. ... Congress' findings are plausible and provide a rational basis for concluding that the Access Act regulates activity which "substantially affects" interstate commerce. Thus, the Access Act is a constitutional exercise of Congress' power under the Commerce Clause.”); U.S. v. Wilson, 73 F.3d 675, 688 (7th Cir. 1995) (“the Access Act may be viewed as a direct regulation of interstate commerce and confirms once again that the Act is well within Congress's power to legislate under the Commerce Clause.”).
Reacting to Dobbs, then, Congress could write a law finding that existing state laws pose a threat to the interstate markets for providing and receiving reproductive services, and then rely on those findings to say that the only limits on abortion are X, Y, and Z, and that states may not impose any additional restrictions.
Could Congress, by preempting state law, make abortion legal in all 50 states? The only thing thing that really matters is whether the Supreme Court would uphold such a law (and it would inevitably end up in front of the Supreme Court). I think it's unlikely, given the current conservative majority on the Court, that it would be upheld.
It appears to be well-established that Congress has broad power to ban things, as long as the Supreme Court is persuaded that those things are a form of "commerce" (and the bar for this is not high). The constitutionality of the Partial-Birth Abortion Ban Act of 2003 was upheld by the Supreme Court in Gonzales v. Carhart. The Opinion of the Court stated that Congress has the power under the Commerce Clause to "regulate the medical profession". Gonzales v. Raich, involving production and consumption of cannabis where no actual commercial activity occurred, and Wickard v. Filburn, involving wheat production where no actual commercial activity occurred, are earlier cases on the same theme.
But does anyone think that Congress could make cannabis legal in all states, preempting state laws to the contrary? Maybe for medical purposes, they could: at least one federal district court has concluded that state bans of FDA-approved prescription drugs are preempted by Federal Food, Drug, and Cosmetic Act. See Zogenix v. Patrick. But it is much harder to imagine that Congress could make recreational cannabis legal in all states and that the Supreme Court would uphold such a law against constitutional challenges. You could try to argue in front of the Court that the exact same power to regulate commerce that allowed Congress to ban cannabis in all states should, by the exact same reasoning, allow Congress to make cannabis legal in all states. I think the odds of this approach working with the conservative majority on the Court are pretty slim.
Or, to give another hypothetical example, could Congress use its Commerce Clause power to make prostitution legal in all states, preempting state laws to the contrary? Again, I think you'd find that the conservative majority on the Court would take a dim view on this. And while abortion is in no way comparable to prostitution, conservatives think that abortion is even worse, because it kills an unborn child. So I think it's unlikely that Congress could successfully preempt state-level bans on abortion.
If the Court had a different ideological composition, it would be really hard to say what outcome would be more likely. There is not a lot of relevant precedent.
The standard way to get near uniform state laws (or lack thereof) on an issue is to dangle bags of money in front of the states. The states all have the power to set their legal driving and drinking ages, as well as their speed limits, to whatever they see fit, but yet these values were remarkably uniform for a time, with most driving ages being 16, most drinking ages being 21, and most highway speed limits being 65. Congress has at various points used federal funding to make this happen; though some have been repealed or altered by this point, or had states decide they didn't wish to participate, resulting in a greater spread of values in the present day. But in any case, by making certain funds contingent upon meeting conditions such as minimum ages, they can persuade states to meet those conditions to save themselves money.
There are SCOTUS-imposed limits on how strong this "persuasion" can be. The requirements have to be meaningfully related to what's being funded and the goal thereof (so putting abortion access requirements on environmental funding won't work), and it can't make up so large a portion of the state budget that it becomes impossible to pass up the funding. Where the line on this is vague, I think it was last placed around .5%.
On average, States spend about 9-10% of their budget on healthcare, with 9-10% of that coming from federal grants. So approximately 1% of state budgets are predicated upon federal healthcare fundings. Make at most half of those (on average) contingent upon meeting some minimum access to abortion care, and you may have yourself a SCOTUS-approvable way to constitutionally persuade, but not mandate, states to pass uniform sets of laws. Some states may forgo this, and clearly with the current SCOTUS there's no telling what prior precedents they'll happily strike down, so there's no guarantees, but it otherwise creates financial pressures by offering alleviation of state budget issues.
The most unassailable way (other than Constitutional Amendment) to make abortion legal, is oddly enough, to make it illegal. If Congress makes it illegal after a certain point, then any attempt to make it illegal BEFORE that point, would run into the Supremacy Clause. This would allow a law that applied to all 50 states (and the territories) to trump any local laws. The more specific they cover, the more difficult it would be to argue they hadn’t carved it out as their own area to decide.