Reid views Warren as someone who can unite the Democratic Party after the longer-than-expected primary battle between Clinton and Bernie Sanders, the source said. The person confirmed a Boston Globe story that reported Reid is actively researching the state’s special election rules.

“He thinks Warren is a good choice to unify the party,” the person close to Reid said.

This is a shift of sorts for Reid, who said recently that he would object to Clinton choosing as vice-presidential nominee any Democratic senator from a state led by a GOP governor with the authority to name the senator’s successor. That could create another hurdle for Democrats looking to regain Senate control this fall.