Bernie Sanders rallied hundreds of supporters outside the New Hampshire capital when the senator formally filed to compete in the state’s first-in-the-nation presidential primary. A howling crowd cheered South Bend, Indiana, Mayor Pete Buttigieg as he walked through the statehouse to file his paperwork.

Michael R. Bloomberg is actively preparing to enter the Democratic presidential primary and is expected to file paperwork this week designating himself as a candidate in at least one state with an early filing deadline, people briefed on Mr. Bloomberg’s plans said.

The U.S. officials who will testify next week at public hearings in the House of Representatives impeachment probe against President Donald Trump include the current top diplomat in Ukraine, the previous ambassador there and a diplomat who has spent much of his career fighting corruption in Ukraine and elsewhere.

Democrats won complete control of the Virginia government for the first time in a generation on Tuesday and claimed a narrow victory in the Kentucky governor’s race, as Republicans struggled in suburbs where President Trump is increasingly unpopular.

House Democrats on Monday released the first transcripts from their closed-door hearings.