Define “liberal”. Depending on place and time the term varies. In some countries, the “liberals” are actually the “conservatives”. Whether “liberal” or “conservative” has little to do with abortion (and related policies such as infanticide, population control, etc.).
Whether it is acceptable for a Jew to support a movement the favors abortion other than when necessary to save the mother’s life, e.g. as a means of population control, or for the convenience of the mother, or to prevent inferiors from reproducing, etc., is a different question that support of overall economic and political policies. Whether you support (or oppose) free trade, or capitalism or democracy, has limited correlation to whether you favor killing babies that someone (not necessarily the mother) doesn’t want.
Whether the Democrats in the 21st century are “liberals” is problematic. Certainly 19th century “liberals” in the Anglo-phonic world would be horrified at many of the policies embraced by today’s Democrats.