The top Democrat on the Senate Judiciary Committee says the panel is starting to see "the putting together of a case of obstruction of justice" against President Donald Trump.

Speaking on NBC's "Meet the Press," California Democrat Dianne Feinstein said the evidence is coming partly from "the continual tweets" from the White House. Trump is focusing renewed attacks on the FBI, and on the investigation by special counsel Robert Mueller, two days after ousted national security adviser Michael Flynn agreed to cooperate with the probe as part of a plea agreement.

Feinstein said she believes Trump's firing of FBI Director James Comey came "directly because he did not agree to lift the cloud of the Russia investigation." She added, "That's obstruction of justice."