Even in tough budget times, there are lines that cannot be crossed. So I was startled by this tidbit reported recently by The Associated Press: When Sarah Palin was mayor of Wasilla, Alaska, the small town began billing sexual-assault victims for the cost of rape kits and forensic exams.

Ms. Palin owes voters an explanation. What was the thinking behind cutting the measly few thousand dollars needed to cover the yearly cost of swabs, specimen containers and medical tests? Whose dumb idea was it to make assault victims and their insurance companies pay instead? Unfortunately, her campaign is shielding the candidate from the press, so Americans may still be waiting for answers on Election Day.

The rape-kit controversy is a troubling matter. The insult to rape victims is obvious. So is the sexism inherent in singling them out to foot the bill for investigating their own case. And the main result of billing rape victims is to protect their attackers by discouraging women from reporting sexual assaults.

That’s why when Senator Joseph Biden, the Democratic vice-presidential nominee, drafted the 1994 Violence Against Women Act, he included provisions to make states ineligible for federal grant money if they charged rape victims for exams and the kits containing the medical supplies needed to conduct them. (Senator John McCain, Ms. Palin’s running mate, voted against Mr. Biden’s initiative, and his name has not been among the long list of co-sponsors each time the act has been renewed.)