The House and Senate have passed their own versions of legislation to reauthorize VAWA. But Democrats favor the Senate version, as it gives tribal courts jurisdiction over domestic abuse cases, creates a pathway to citizenship to illegal aliens who are victims of domestic abuse and expands the availability of related visas.

Leahy and Murkowski reiterated these points in their letter to BoehnerJohn Andrew BoehnerJohn Feehery: A political forest fire Trump's pick for Federal Reserve chief is right choice at right time The two-party system is dying — let’s put it out of its misery MORE.

"We should not let politics pick and choose which victims of abuse to help and which to ignore," they wrote. "However, this fundamental principle is not reflected in the House version of VAWA reauthorization legislation."

While House and Senate passage of a bill normally leads to a conference to reconcile the two bills, no conference meetings have happened. Republicans have said the Senate bill includes a revenue measure, which normally must originate in the House, and that this has caused a so-called "blue slip" problem that prevents a conference.

Democrats have argued that Republicans are using this problem as an excuse for not moving ahead with the bill in conference.