When Donald Trump promised to drain the swamp, we didn’t realize it would start with his inner circle. Trump confidante Lieutenant General Michael Flynn is out after being exposed for being less than truthful with the vice president and the FBI about dodgy discussions he had with the Russian ambassador the day President Obama sanctioned Moscow for interfering in the election. Flynn’s 24-day tenure as national security adviser was the shortest in history — half the average life span of a female mosquito. But don’t assume the swamp is drained.

There are new reports of repeated contacts during the campaign between Russian intelligence agents and Trump aides. We don’t know where this story ends, but we do know the central question: Is something rotten in the White House?

We also know, given the pattern of deceptions from the White House, what the next step should be, irrespective of partisan loyalties and agendas: Congress must take up its constitutional duty and investigate any interests or actions that might undermine our democracy.

In the Flynn saga, the question inevitably is this: Following Russian hacking and front-page reporting on intelligence probes of links between Moscow and team Trump during the campaign, wouldn’t an incoming national security adviser consult and inform the president-elect about his conversations with the Russian ambassador?

Flynn told Vice President Mike Pence (and reportedly FBI investigators) that he hadn’t talked about sanctions with Ambassador Sergey Kislyak. But here’s the rub: US intelligence monitors ambassadors’ calls, and the Justice Department thought Flynn’s comments might violate the Logan Act, which prohibits private citizens from negotiating with foreign governments. The acting attorney general warned the White House that Flynn could be vulnerable to blackmail for lying. Even after The Washington Post broke the story, Flynn continued denials before finally admitting that he and Kislyak had “a brief discussion.’’ According to Flynn, he told Kislyak, “Look, I know this happened. We’ll review everything’’ once Trump is president.

Orwellian is a charitable word for Trump’s effort to ignore, bury, deny, and finally divert attention from Flynn’s actions by claiming the “real story’’ is “leaks.’’ Trump tweeted angrily Wednesday that The New York Times and Washington Post got information “illegally.’’ Keep in mind the public, and as far as we know, the vice president, learned about Flynn’s calls from those newspapers, not the president. This is where Congress comes in.

“These activities border on the treasonous,’’ said Representative Jim Himes, a Connecticut Democrat on the House Permanent Select Committee on Intelligence, which is investigating Russian interference in the election. “Right now, no one knows who in the White House had knowledge of or input into Flynn’s calls. I believe there are transcripts of those calls, which we should see.’’

Committee chairman Devin Nunes, a California Republican, disagrees, saying Flynn has privacy rights and leaks are the bigger problem.

Representative Adam Schiff of California, the ranking Democrat on the committee, said Republicans don’t want to challenge Trump: “They want to get everything they can from this president before the wheels come off, and they don’t want to antagonize’’ and become the target of his wrath on Twitter or elsewhere.

Consider Kentucky Senator Rand Paul, who said as much on Fox Radio: that if Republicans waste time investigating Republicans, “we’ll never get started with doing the things we need to do, like repealing Obamacare.’’

Himes expects this attitude to change, and it may change fast. “The more the president becomes a political liability, the more I expect Republicans will find their voice,’’ he said. Senate majority leader Mitch McConnell said an investigation of Flynn is “highly likely,’’ and Senate Select Committee on Intelligence Chairman Richard Burr of North Carolina said he wants to see transcripts of those calls.

We don’t know yet where this story ends, but it’s the duty of Congress to find out how high the swamp rises. Do your job.

Indira A.R. Lakshmanan is a Washington columnist. Follow her on Twitter @Indira_L.