'HOW FAR UP DID IT GO?': Lawmakers say Russia controversy does not end with Michael Flynn

Democratic lawmakers say there are still many unanswered questions after Trump's national security adviser Michael Flynn resigned on Monday evening.

Several have asked whether Flynn's apparent close communications with Russia could have compromised parts of the Trump administration. "Flynn's resignation is a good [first] step. If colluding with Russia on sanctions is unacceptable, what about colluding with Russia on the campaign," Rep. Jaime Raskin of Maryland said in a message posted on Twitter.

A tweet sent from former Colorado Rep. John Dingell's Twitter account said: "Flynn's resignation CANNOT be the end of the story. Who talked to who? When? Who knew? ... How far up did it go?"

Sen. Chris Murphy of Connecticut said, "Flynn's departure only matters if 1) He's followed by a mainstream, experienced replacement, 2) We get to bottom of the Trump/Russia story."

"General Flynn's resignation is a step in the right direction, but many questions remain," Texas congressman Joaquin Castro said Monday night.

An assessment by former deputy US attorney general Sally Yates that The Washington Post cited Monday night suggested that Flynn, who had contact with Russia's ambassador to the US, Sergey Kislyak, may be subject to blackmail from Russia. Former Director of National Intelligence James Clapper and former CIA Director John Brennan both concurred, saying "Flynn had put himself in a compromising position," with Russia.

That assessment is an extension of a long-playing narrative surrounding President Donald Trump, who has often expressed an affinity for Russian President Vladimir Putin.

During and after his election campaign, Trump has made clear that he revered Putin's leadership of Russia and, at one point, made a direct appeal to the Kremlin during a news conference, asking Russia to find damaging information on his then-rival, Hillary Clinton.

A classified dossier on Trump, compiled by a former British spy, also contained allegations about Trump's alleged associations with Russia. Though some details in that 35-page document have not been verified, US officials said on Friday that some elements were indeed accurate.

Business Insider's Natasha Bertrand reported on Saturday that the timeline of Trump's ties with Russia in that dossier line up with allegations of conspiracy and misconduct. That dossier is still being investigated.