WASHINGTON — After the Senate’s derailing of Republican legislation halting federal dollars for Planned Parenthood, one thing seems clear: Many on both sides think they can ring up gains from the battle.Abortion-rights groups are already releasing TV ads attacking GOP supporters of the measure for stomping on women’s health-care needs. Conservatives are accusing Democrats of voting to protect taxpayer funds for an organization whose campaign contributions tilt lopsidedly to Democratic candidates.And each …