The top Democrat on the Senate Intelligence Committee called for more investigation into the digital activities of Donald Trump's campaign, amid concerns about Russian-directed misinformation efforts to influence the election, even as the president's lawyer vigorously defended his client.

Sen. Mark Warner of Virginia said he wants to look into the activities of Cambridge Analytica, a data firm that advised Trump's campaign, as well as Trump's digital efforts during the election because of the way false election stories about Hillary Clinton were circulated and targeted online.

"The ability to manipulate these search engines and some of these social media platforms is real, it's out there," Warner said on CNN's "State of the Union" on Sunday. "We need information from the companies, as well as we need to look into the activities of some of the Trump digital campaign activities."