Donald Trump's presidency is in danger of being undone by Terrible Tuesday - August 21, 2018. Picture: Alex Brandon/AP/African News Agency (ANA)

Washington - Donald Trump probably would not have become president without his victory in seven of the 11 primaries held on Super Tuesday, March 1, 2016. Now his presidency is in danger of being undone by Terrible Tuesday - August 21, 2018. This was the day when his campaign manager, Paul Manafort, was convicted of eight felony counts in a Virginia courtroom and his personal lawyer, Michael Cohen, pleaded guilty to eight felony counts in a New York courtroom.

The Manafort charges of tax and bank fraud do not directly implicate the president, but they do vindicate the special counsel, Robert Mueller, showing that his inquiry is no "Rigged Witch Hunt" but a serious investigation that has produced 35 indictments, six guilty pleas and one conviction. No special counsel has done more, faster. If Manafort had been found not guilty, it would have been a massive blow to Mueller. Because he was found guilty, it is a blow to Trump.

But not nearly as big a blow as Cohen's admission under oath that he violated federal campaign laws by arranging illicit payments to adult-film star Stormy Daniels and Playboy playmate Karen McDougal "in coordination with and at the direction of a candidate for federal office." For the first time since Watergate, the president is now an alleged co-conspirator in the commission of a federal crime. As Cohen's lawyer, Lanny Davis, said, his client "testified under oath that Donald Trump directed him to commit a crime by making payments to two women for the principal purpose of influencing an election. If those payments were a crime for Cohen, then why wouldn't they be a crime for Donald Trump?"

And Cohen may have only begun implicating the president. Davis said on MSNBC that Cohen would be happy to share other incriminating information with the special counsel, including "knowledge about the computer crime of hacking and whether or not Mr. Trump knew ahead of time about that crime and even cheered it on." This would seem to vindicate an earlier leak that Cohen may be able to provide the "smoking gun" evidence showing that Trump himself gave the go-ahead to collusion with the Kremlin.

In short, there is growing evidence that the president is, to use the label favored by Richard Nixon, "a crook." Even buying the silence of his reputed playmates could by itself have been enough to swing an exceedingly close election decided by fewer than 80,000 votes in three states. Trump certainly would not have authorized the payments unless he thought it was politically imperative to do so. There is also considerable evidence, as I previously argued, that Russia's intervention on Trump's behalf affected the outcome. Even more than Nixon, Trump is now an illegitimate president whose election is tainted by fraud.

The inevitable question is: Now what? If Trump had an iota of decency, he would resign. But he doesn't, and prevailing Justice Department guidelines hold that a president can't be indicted while in office. So the onus is on Congress to act. A responsible Congress would have already convened an impeachment inquiry by now. But that is not the Congress we have. We have a Congress dominated by political hacks and moral invertebrates who are determined to act as the president's enablers and legitimisers at all costs.

It tells you all you need to know about the moral standing of Trump's defenders that Terrible Tuesday also included the indictment of one of his earliest congressional supporters, Rep. Duncan D. Hunter, R-Calif., and his wife on charges of misusing campaign funds to pay personal expenses. This comes shortly after another of Trump's early endorsers, Rep. Chris Collins, R-N.Y, decided not to seek re-election after being indicted on insider-trading charges.

But the far more serious crimes of Trump's congressional supporters do not involve personal peculation. They involve violating their oaths of office by failing to hold the president accountable for misusing his office. Some, such as Rep. Devin Nunes, R-Calif, and Rep. Jim Jordan, R-Ohio, have gone much further by actively attempting to impede the Justice Department investigation into Trump's alleged misconduct. They have become, in a moral if not legal sense, accessories to obstruction of justice.

And they have gotten away with it because the congressional leadership has allowed them to do so. Judging by Tuesday's cowardly and cautious statement from House Speaker Paul Ryan, R-Wis. ("We are aware of Mr. Cohen's guilty plea to these serious charges. We will need more information than is currently available at this point"), there is no sign that the Republicans in Congress will ever provide any serious oversight of the Republican in the White House.

The voters of the United States must now say to this Congress what Oliver Cromwell said to the Rump Parliament in 1653: "Ye are a factious crew, and enemies to all good government... Ye are grown intolerably odious to the whole nation. You were deputed here by the people to get grievances redressed, are yourselves become the greatest grievance... Go, get you out! Make haste!... In the name of God, go!"