Do the DemocRATS really want to vote on this bill? There are quite a few “conservative Democrats” who got elected by paper thin margins in Republican districts last November.
Most of the truly vulnerable pro-life Republicans were defeated in 2006. Some were defeated by Democrat candidates running as pro-lifers. Many of them will be pressed to betray their pro-life promises. Pro-lifers of both parties will hammer them out of office as liars on this unforgiving issue. This bill would legitimatize partial birth abortion along with the rest. There will be ads with film of the 2006 pro-life promises followed by the graphics of scissors puncturing the skull and infant slaughtered by suctioning out the living brain. You are right that many Democrats won't want to vote on this but they will have to one way or another.
Demonrat leadership will want to avoid embarassment and will pressure the weak freshmen in what is, for pro-aborts, an increasingly lost cause. If the Demonrat leaders press hard enough, they lose their House majority and some Senate races that might otherwise have been won. There may even be a party defection or two.
Be not afraid. For all the things that matter, carry on.