FactCheck's take on this:
The ad refers to a bill Obama supported in the Illinois state Senate to update the sex education curriculum and make it "medically accurate." It would have lowered the age at which students would begin what the bill termed "comprehensive sex education" to include kindergarten. But it mandated the instruction be "age-appropriate" for kindergarteners when addressing topics such as sexually transmitted diseases...The bill also called for all sex education course materials to include information that would help students recognize, among other activities, inappropriate touching, sexual assault and rape...The bill passed in the Health and Human Services Committee with Democrats, including Obama, voting along party lines in support of it. But the measure promptly stalled and died in the full Senate, and no action has been taken on it since late 2005.Here's the bill itself. Read it and see what you think.