WASHINGTON — The Biden administration is preparing for a worst-case scenario if a conservative federal judge rules in favor of a lawsuit seeking to restrict access to one of the two drugs typically used to induce a medicated abortion.Two drugs, mifepristone and misoprostol, can be taken by women at home and are used for just over half of U.S. abortions. But that could be quickly changed by a lawsuit filed by an anti-abortion group in Texas that claims the Food and Drug Administration wrongly approved mifepristone for …