Republicans and Democrats Face Leadership Struggles as House Returns

The House returns from its July Fourth recess this week in a state of remarkable uncertainty, with both Democrats and Republicans facing open questions about their leaders’ futures and neither party sure about which will be in control after November’s elections.“Sometimes things have to be torn down before they can be built back up,” said Representative Brian Higgins, Democrat of New York. “And I think we are in the tearing down phase, at least in the House.”

For Democrats, the loss in a primary last month of a popular lawmaker seen as a potential House speaker has injected new complications into an inevitable and messy struggle over control of the caucus.

In some quarters, simmering frustration with their longtime leader, Representative Nancy Pelosi of California, 78, has given way to whisper campaigns among potential challengers and public calls for the passing of the baton to a younger generation. Her top lieutenant and longtime rival, Representative Steny H. Hoyer of Maryland, 79, checked into a Washington hospital with pneumonia last week, underscoring the concerns among some in the party about the age of the current leadership.

With the retirement of Speaker Paul D. Ryan of Wisconsin at the end of the year, Republicans face their own fight for control. The embarrassing rout of “compromise” immigration legislation last month resurfaced concerns that Mr. Ryan’s power may be waning. And while the party has a clearer order of succession, it remains to be seen if Representative Kevin McCarthy of California, the majority leader, can consolidate the support to replace Mr. Ryan.