Sensing a political opportunity they have not had in more than a decade, social conservatives are preparing for a lengthy fight over abortion rights that promises to widen the culture war fissures that Republicans have tried for years to bridge. Two fights loom in Washington that are galvanizing the right as it solidifies control of two branches of government and moves to dominate the third: an effort in Congress to eliminate Planned Parenthood’s federal funding and President Donald Trump’s forthcoming choice of a Supreme Court nominee.