WASHINGTON — With Democrats increasingly confident they will win control of the House next month and hopeful of a majority in the Senate, party leaders are turning to the next challenge: deciding what they will do with their power if they get it.

For months, they have promised voters they will address an “affordability crisis” they blamed on failed Republican policies, pledging to lower the high cost of groceries, gas and healthcare. And they have vowed to combat what they say is rampant corruption by President Donald Trump and his administration, though they have shied away from promising an impeachment after their first two efforts to remove him from office failed.

Should they win in November, top House Democrats are planning a shock-and-awe legislative sprint to demonstrate within hours of taking power that they are passing bills to deliver on their promises, including restoring healthcare subsidies and Medicaid resources and moving to end Trump’s tariffs and the war with Iran.

They will face steep…