1. Two top Obama administration officials testified before the Senate about Russia’s interference in the presidential election and the role of Michael Flynn.

Sally Yates, the former acting attorney general, said she warned the White House that Mr. Flynn, who was named the president’s national security adviser, was susceptible to Russian blackmail. He was fired more than two weeks later.

Separately, former Obama staff members told us that President Obama had warned Donald Trump not to hire Mr. Flynn when they met in the Oval Office two days after the election.