There’s a reason anti-choice groups are celebrating Donald Trump’s decision to tap Indiana Gov. Mike Pence as his running mate: Pence has spearheaded congressional efforts to defund Planned Parenthood, even if it meant shutting down the government, signed anti-abortion measures into law in Indiana and rallied opposition to President Obama’s effort to roll back prohibitions on stem-cell research.

Pence, who pledged at an anti-choice rally to send Roe v. Wade, which he called “the worse Supreme Court decision since Dred Scott,” to “the ash heap of history,” also cosponsored anti-choice “personhood” resolutions while serving in Congress.

The Life at Conception Act, which Pence cosponsored, called for Congress to “implement equal protection under the 14th article of amendment to the Constitution for the right to life of each born and preborn person,” defining legal personhood as beginning at the “moment of of fertilization.”

Pence also cosponsored the Right to Life Act, a similar personhood bill.

Advocates of federal personhood bills believe that if Congress passes legislation defining “personhood” as beginning at conception, they can bypass and nullify Roe v. Wade, criminalizing abortion nationwide with no exceptions. While the personhood movement has traditionally sat on the far-right fringes of the anti-abortion movement, in recent years Republican politicians like Pence have brought the extremist cause into the GOP mainstream. Unlike more established abortion rights opponents that seek to cut off access to abortion and gradually outlaw the procedure, personhood activists want the government to immediately end abortion in all cases.

Trump, of course, has taken several contradictory positions on abortion rights throughout the campaign, including saying that women who have abortions should face legal punishment. While many anti-abortion groups condemned his remarks, his call for punishing women who have abortions was completely compatible with the message of personhood groups like Personhood USA, which praised the prosecution of a Tennessee woman for murder last year after she attempted a do-it-yourself, coat-hanger abortion.

Now, with Pence as his running-mate, Trump has decided to fully bring the personhood movement into his campaign.