Abortion has been a big issue outside of the Democratic National Convention this week. There have been protests and arrests.
One group even put a massive banner on the side of a Denver mountain that called the Democrats the party that "destroys unborn children."
But one pro-life Democrat is trying to convince abortion opponents to vote for Barack Obama.
"Now Barack Obama and I have an honest disagreement on the issue of abortion," said Sen. Bob Casey, Jr. D-Pennsylvania. "But the fact that I'm speaking here tonight is testament to Barack's ability to show respect to the views of people who may disagree with him."
Casey is a Catholic. His father, former Pennsylvania Governor Robert Casey was not invited to speak at the nominating convention for Bill Clinton 16 years ago, because of his anti-abortion views.