Casey does say, though, "Adoption of the undue burden standard does not disturb Roe's holding that regardless of whether exceptions are made for particular circumstances, a State may not prohibit any woman from making the ultimate decision to terminate her pregnancy before viability" (Planned Parenthood of Southeastern Pa. v. Casey (91-744), 505 U.S. 833 (1992), <http://www.law.cornell.edu/supct/html/91-744.ZS.html>), so the concept of viability survives in law, though reality is that many burdens have been judged to not to be undue and the post-O'Connor court is likely to be more willing to allow states to impose more burdens.
The trimester division survives in practice, too, in a negative way: women, especially young women, who may not realize or are in denial about their pregnancy beyond the first trimester end up having even more trouble finding abortion providers than other women. Whenever we have discussion about abortion, someone raises the specter or a woman willfully having an abortion very, very late in pregnancy. The reality is, however, most women who decide to have abortion do so as soon as their financial and other circumstances allow (early abortions are easier and cheaper), and few providers actually perform abortions after the first trimester, to the detriment of most vulnerable and resourceless women.
Getting back to the poll that Doug posted, the struggle is really over the hearts and minds of former liberals, since it is their move to the center, not former conservatives' move to the center (which is actually welcome), that is the main problem, and the main struggle will be at the state level. -- Yoshie <http://montages.blogspot.com/> <http://mrzine.org> <http://monthlyreview.org/>