With a deeper-than-ever split between Republicans and Democrats over abortion, activists on both sides foresee a presidential campaign in which the volatile topic is talked about more than in past elections.

Stages of a fetus are displayed at the Illinois Right To Life table in Tinley Park, Illinois. (Photo by Scott Olson/Getty Images)

Hillary Clinton has voiced strong support for planned parenthood--a major provider of abortions.

Nearly all of the GOP candidates favor outlawing abortion in the U.S.

Typically, candidates have tried to avoid this issue but Republicans in particular are being more vocal about positions that could alienate women voters.