Even in the ultrapolarized atmosphere of Capitol Hill, it should be possible to secure broad bipartisan agreement on reauthorizing the Violence Against Women Act, the 1994 law at the center of the nation’s efforts to combat domestic violence, sexual assault and stalking. The law’s renewal has strong backing from law enforcement and groups that work with victims, and earlier reauthorizations of the law, in 2000 and 2005, passed Congress with strong support from both sides of the aisle.

Yet not a single Republican on the Senate Judiciary Committee voted in favor last week when the committee approved a well-crafted reauthorization bill introduced by its chairman, Senator Patrick Leahy, and Senator Michael Crapo, a Republican of Idaho, who is not on the committee.

The bill includes smart improvements aimed, for example, at encouraging effective enforcement of protective orders and reducing the national backlog of untested rape kits. The Republican opposition seems driven largely by an antigay, anti-immigrant agenda. The main sticking points seemed to be language in the bill to ensure that victims are not denied services because they are gay or transgender and a provision that would modestly expand the availability of special visas for undocumented immigrants who are victims of domestic violence — a necessary step to encourage those victims to come forward.

Senator Charles Grassley, the committee’s ranking Republican, offered a substitute bill that not only cut out those improvements but called for a huge reduction in authorized financing, and elimination of the Justice Department office devoted to administering the law and coordinating the nation’s response to domestic violence and sexual assaults. His measure was defeated along party lines.