One thing you'll hear lawmakers on both sides of the abortion debate say again and again is that federal money shouldn't be used to pay for abortions. There's no reason that taypayer money shouldn't fund a legal medical procedure, but thanks to the Hyde Amendment, which just turned 35, most Americans don't question that logic.
The Hyde Amendment was passed in 1976, three years after Roe v. Wade. As RH Reality Check notes, at the time Rep. Henry Hyde, the bill's sponsor, actually said that his aim was to stop abortion altogether:
"I certainly would like to prevent, if I could legally, anybody from having an abortion, a rich woman, a middle-class woman, or a poor woman. Unfortunately, the only vehicle available is the [Medicaid] bill."
This was the beginning of the anti-choice movement's strategy of limiting abortion access even though it couldn't outlaw the procedure entirely. As usual, it hit poor women the hardest by ensuring Medicaid and other government programs won't fund an abortion. At first there wasn't even an exception for cases of rape, or when the woman's life was in danger, but this was added after pro-choice groups protested.
Over the years, the rider, which is attached to appropriations bills every year, came to be seen as an important compromise in the battle over abortion. The Washington Post reports that when the issue came up during the healthcare reform debate, President Obama said, "I'm pro-choice, but I think we also have the tradition in this town, historically, of not financing abortions as part of government-funded health care." After months of debate, he wound up issuing an executive order that upheld the Hyde Amendment and still managed to piss everyone off.