Updated 3:32 p.m.

The political firestorm that Rep. Todd Akin, R-Mo., ignited with his now-recanted claim that  women rarely getting pregnant from “legitimate rape" has focused attention on an unusual fact about the crime: When speaking of it, politicians often use a qualifier.

A search of the Congressional Record using the Sunlight Foundation's Capitol Words tool shows no instances of other lawmakers using the phrase or advancing the odd biological theory that has led Republican leaders from Mitt Romney to Sen. Mitch McConnell, R-Ky., to urge Akin — a member of the House Science Committee — to quit the Missouri Senate race.

But there are plenty of members of both parties who have employed a slightly different term, one that Akin said he meant to use in his disastrous interview: forcible rape. You can see a graph of the frequency of usage below. Click on the "by party" button and you can see that Democrats use the term as well as Republicans.

Most often the phrase is used quoting statistics from the FBI, or in arguing for increased criminal penalties. One reason is that the phrase is a legal term of art that distinguishes between rapes that are violent and rapes that are perpetrated on victims who are drugged, below the legal age of consent, or bullied into so-called "date rape."

Vice President Joe Biden, was one of the top users of the phrase “forcible rape” during his tenure in the Senate. Author of the Violence Against Women Act, Biden has quoted the forcible rape statistic on record four times. 

But lately the term "forcible rape" has taken on political overtones. The term was used several times in reference to H.R. 3, No Taxpayer Funding for Abortion Act. In the bill, the definition of rape was narrowed so that fewer women who had been raped would be eligible for abortions covered by insurance. One of the top users of "forcible rape" is Rep. Chris Smith, R-N.J., one of Capitol Hill's most outspoken opponents of abortion and the author of H.R. 3. The bill passed the House with the support of all but five Republicans, but was blocked in the Democratic-controlled Senate. Among the original co-sponsors of the bill, which was later amended to remove the term "forcible rape:" Rep. Paul Ryan, R-Wis., the GOP's vice presidential nominee-to-be.

This year, Rep. Debbie Wasserman Schultz, D-Fla, her party's national chair, used the term critically, arguing that the phrase ‘forcible rape’ is a means for limiting women's reproductive rights. In a House floor speech on the anniversary of Roe v. Wade, the 1973 Supreme Court decision that made abortion legal nationwide, Shultz said:

Last year, the Republican majority in the House took up a slew of bills that tried to do everything from defund Planned Parenthood, a crucial title X provider in our country, to redefine rape to say that if the victim was mentally unable to consent, then it didn't really count as forcible rape.

Earlier this year the Justice Department announced it is broadening the federal definition of rape for crime reporting purposes to include a wide range of sexual assaults against men and women. The original definition, which dated from 1927, classified a rape as "carnal knowledge of a female, forcibly and against her will."  Under the new definition, which will take effect in 2013, federal officials will make no distinction between "forcible" and "non-forcible" rape when the crimes are reported.

Leila Abolfazli, senior counsel at the National Women’s Law Center sees a political motivation behind the effort to distinguish between types of rape:

Crazy policy statements and whittling down the definition rape are aimed at restricting access to abortion. This is part of a much broader force with different tactics and antics — the same idea as the Ultrasound laws and making compliance standards burdensome. They say it is for women’s health but it is really about shaming women and shutting down clinics.

One interesting use of “forcible rape” that our Capitol Words serched turned up: Former Sen. John Ensign, R-Nev., speaking in 2006 about amendments to the Child Custody Protection Act. Ensign, later forced out of office in an adultery scandal, argued that underage girls crossing state lines to have an abortion were destroying evidence:

So typically, you would have a teenage girl with a boyfriend who is significantly older than her. And in the context of that relationship, the young girl becomes pregnant. Sometimes that pregnancy is the result of a forcible rape, where the girls does not consent; in most cases, it is at least statutory rape. This legislation will help law enforcement stop adult men from preying upon underage girls and violating the law with respect to the crime of rape–statutory or otherwise. Which is the right thing to do. This bill makes it a further crime if that male takes this young girl across State lines to get an abortion to cover up his tracks, basically to try to eliminate the evidence of his crime.