Katherine Clark is now the highest-ranking woman in Congress. Will she and the new Democrats atop the House remake the party, or just carry on the last generation’s legacy?

Nancy Pelosi will give way to a younger core of party bosses who will need to quickly learn how to share power—and be a minority party.

Katherine Clark is both a progressive pugilist and bipartisan realist. That might be exactly what the Democratic opposition needs under a Republican government.