So former United States national security adviser Michael Flynn has pleaded guilty to lying to the FBI in the federal investigation into Russia’s alleged interference in the 2016 presidential election.

The big worry for Trump is that Flynn has agreed to cooperate with the ongoing investigation into alleged Russian meddling in the election, led by special counsel Robert Mueller.

Retired judge and Fox News analyst Andrew Napolitano says this is “probably the tip of a prosecutorial iceberg”.

According to court documents, Flynn clearly lied to the FBI when he was asked about his dealings with the Russian ambassador.

ABC News reports that Flynn is now prepared to testify that Donald Trump directed him to make contact with the Russians,

At the same time, there are reports that Donald Trump’s son-in-law Jared Kushner told Flynn to call members of the U.N. national security council, and encourage them to block a resolution condemning Israel’s illegal settlements in the West Bank, in defiance of the Obama administration’s wishes. Flynn subsequently contacted Russian ambassador Sergey Kislyak, and asked him to impede the vote against Israel’s settlements. Shortly thereafter, Trump’s first national security adviser told the FBI that he’d never done any such thing.

That was in December 2016. Obama was still president, putting Flynn and Kushner in violation of the Logan Act, a 1799 statute that prohibits private U.S. citizens from undermining the foreign policy of a sitting U.S. president through contact with a foreign power.

This is significant. As Richard Silverstein writes in the Tikun Olam blog, lying about one’s action pursuant to a Logan Act violation is an eminently prosecutable offense. That’s perjury and a standard federal case. This is what Flynn has confessed to.

“Next up, without doubt, will be Kushner,” Silverstein writes. “He’s next in Mueller’s sites. But unlike Flynn, he can’t cop a plea. If he did so, this would lead directly to Trump, since Kushner without doubt pursued this matter under direct order from Trump. Kushner must protect the big guy. That’s why it’s likely Mueller will actually file charges against Kushner, indict him and prosecute him. Whether he wins the case will determine whether Trump goes down as the next target.”

So the big fish is Donald Trump and Mueller is looking to present the evidence to Congress that will seal Trump’s impeachment.

The bottom line however is that Republicans hold majorities in both the House and the Senate. That means they still hold the cards when it comes to Trump’s future. Whatever the FBI concludes, it can only present evidence to Congress about Trump. It’s up to Congress to start impeachment proceedings against the president.

That’s unlikely with the GOP in control.

Of course, that could change after next year’s mid-term elections but Trump is no pushover. His notorious combativeness and ability to wriggle out of trouble won’t make his impeachment easy and quick. More to the point, it won’t make it certain.

All Trump needs to stay in power and take over American government is a grave national or international crisis.

Like for example a nuclear war with North Korea.