With the South Carolina special election on Tuesday, all eyes are on Elizabeth Colbert Busch, the 58-year-old political novice who has a coin-toss chance of becoming the first Democrat to represent the state's First Congressional District in more than thirty years, and the second woman ever to do so. It's no surprise, then, that some of her opponents would stoop pretty low to keep her out of office. Sure enough, ThinkProgress reported last week that an unknown polling group had been calling voters and asking misleading, unabashedly sexist questions, including “What would you think of Elizabeth Colbert Busch if I told you she had had an abortion?”

The calls are thought to be a “push poll”—a negative campaign stratagem disguised as a poll, intended to make insinuations about an opponent and not to collect information. With this unsavory incident added to the list, South Carolina probably leads the nation in outlandish smear campaigns. In 2000, John McCain lost the presidential primary in part thanks to a rumor that he had fathered an illegitimate black child. In 2010, current Governor Nikki Haley was accused of sleeping with an assortment of political consultants. Just last winter, Newt Gingrich fended off reports that he had forced his ex-wife to have an abortion.

Smears about abortion have a rich history outside of South Carolina as well. Abortion is such a four-letter word in conservative districts, politicians often try to pin their opponents with some connection to the procedure. Usually, when the candidate is male, the insinutation is that he allowed, or even forced, a wife, girlfriend, or daughter to get one. When the candidate is female, the smear can be even more direct: that she ended a pregnancy herself.

Typically, the women who have suffered this particular attack were pro-life Republicans, unlike the socially liberal, pro-choice Colbert Busch. Sue Myrick of North Carolina, until recently a member of the U.S. House of Representatives, ran for her party’s Senate nomination in 1992. When she lost, she claimed her opponent’s supporters had run a phone and mail campaign accusing her of having an abortion, among other things. “Everything was a lie,” she said then. “If I had been a male, they couldn't have gotten away with any of this. People would have dismissed it.” In another Republican primary, for a Florida state senate seat in 1996, Charlie Clary reportedly arranged a push poll to target his female opponent. “Would you be more or less willing to vote for Lois Benson if you knew she had an abortion?” it asked. Clary beat Benson for the nomination.

Women politicians have also used this tactic against each other. In 2003, Democratic state Senator Barbara Blackmon faced off against Republican incumbent Amy Tuck for Lieutenant Governor of Mississippi. Trying to counteract the perception that she was pro-choice, Blackmon proposed that both candidates sign an affidavit swearing they had never had an abortion. Tuck called the move an “innuendo” meant to suggest to voters that she had, in fact, had an abortion. Outraged, she told the AP at the time, “I have not had an abortion. I am pro-life in my private life and I am pro-life in my professional life. I've seen a lot of low-road politics in my time, but this beats all.” That time, the move backfired, and Tuck bested Blackmon.