Republican John McCain, an abortion rights opponent with a conservative Senate record on the issue, seems content with the public's perception that he's more moderate on the subject.

Democrat Barack Obama, who supports abortion rights, is only too happy to remind voters where McCain stands, but he tries to make his case without attracting too much attention.

Both presidential candidates are gingerly trying to strike the right chord on abortion as they reach out to a critical voting group — independents and moderates, primarily women in swing-voting suburban regions of crucial states such as Pennsylvania, Michigan and Ohio.

The candidates' carefully targeted ads on abortion and stem-cell research, topics that enflame passions among both abortion-rights proponents and opponents, illustrate how Republicans and Democrats alike are tailoring their messages to specific groups of voters.

Obama criticizes McCain in ads that say the GOP nominee takes an "extreme position on choice" and "will make abortion illegal." That misrepresents McCain's position. The Arizona senator favors overturning the Supreme Court's guarantee of abortion rights but would let states decide their own abortion laws, and he is not seeking a constitutional ban.

Obama is using low-profile radio ads and campaign mailings to make his point about McCain. He hopes to avoid being tagged as too liberal on abortion.

McCain, for his part, is responding with radio commercials promising to support stem cell research to "unlock the mystery of cancer, diabetes, heart disease." He doesn't mention that he supports embryonic stem cell research, which many anti-abortion Republicans oppose.