At the same time, I am always surprised by the extent to which my fellow pro choice advocates misread public opinion on the issue. They take a "me and my friends agree so everyone else must agree, too" attitude. Here's a classic example from a classic "progressive" blog:
Several undecided House Democrats came out in support of the health insurance bill today, but it's still not clear whether leaders have the 216 votes they need. Between six and twelve Democrats are in Bart Stupak's bloc, which will vote for the bill only if it severely restricts private insurance coverage for abortions. . . . Given how much Democrats rely on women voters to win elections, it's amazing that they would sell out abortion rights to appease a few anti-choicers.http://mydd.com/2010/3/19/stupak-may-yet-bring-down-this-bill
They really believe that all women are pro choice, and that the anti choice position is held by only "a few anti-choicers".
No wonder they can't get anything done with super majorities.