If Democrats retake the House in November, Hakeem Jeffries is all but certain to become speaker in January — the first Black American to hold the post.

Yet the question facing the 56-year-old New York lawmaker is not whether he can make history, but how he would lead — specifically, whether the consensus-building style that helped him rise through the ranks to minority leader can hold together what is expected to be an increasingly restive and ideologically diverse Democratic caucus.