WASHINGTON — Republicans have seized on gas prices as their motivating political issue of the moment. House Democrats cling to the Ryan budget as the document that is going to propel them back to power when voters recoil at its spending cuts. But the political weapon of choice for Senate Democrats is the plight of women, and they appear to have no intention of letting it go.

On Wednesday, three female Democratic senators held a news conference to denounce Republican opposition to the reauthorization of a measure to counter domestic violence even though the bill appears to have more than enough official sponsors — including Republicans — to get over the finish line.

Vice President Joseph R. Biden Jr. picked up the thread and also lauded the legislation — the Violence Against Women Act — which he wrote when he was a senator and helped enact in 1994 — and further criticized Republicans.

“What are we arguing about?” Mr. Biden asked. “This shouldn’t be hard.”

Further, Senate Democrats are planning to soon bring a bill to the floor — one that failed in 2010 — that would strengthen federal pay-equity laws.