John Avlon is a CNN senior political analyst and anchor. The opinions expressed in this commentary are his own. View more opinion articles on CNN.

(CNN) "Drain the swamp" was a popular chant at Trump rallies in 2016, ranking second only to the cries of "Lock Her Up" that still persist as a greatest hit at his presidential arena tours.

Nineteen months into the Trump administration, we're starting to see what a real culture of corruption looks like. None of it is normal.

Last week, the President's campaign chairman Paul Manafort and his personal lawyer, Michael Cohen, became convicted felons. His first national security adviser, Gen. Michael Flynn, has pleaded guilty to lying to the FBI. So did Manafort aide Rick Gates and Trump's campaign foreign policy adviser George Papadopoulos, whose bragging about how he knew the Russians had dirt on Hillary Clinton kicked off the Russia investigation. And with a second Manafort trial yet to come and the Mueller investigation still incomplete, there may very well be more convictions on the horizon.

No wonder we've now been treated to the spectacle of the President of the United States musing to Fox News about how there "almost" should be a law that makes "flipping" illegal . For mob bosses, and in popular culture, giving evidence to law enforcement spawned the phrase "snitches get stitches." It is also known as finally telling the truth to prosecutors when under oath.

The way we know this isn't normal is that we can compare the Trump presidency with those of his predecessors. And the comparison ain't pretty.

Let's narrow the comparison to a look at how many members of the different administrations' executive branch became convicted felons in the 50 years since Richard Nixon was elected.

Counting backwards, we'll start with President Trump's nearest predecessor, President Obama.

After all, it was the Obama administration that Trump and his followers were targeting most directly with the talk of draining the swamp and the culture of government corruption. But it turns out that over eight years there was only one person in the Obama executive branch who pleaded guilty to a crime -- and it was a misdemeanor. That would be then-CIA director David Petraeus, who pleaded guilty to one count of removing and retaining classified information in conjunction with a tawdry affair. He received two years probation and paid a $100,000 fine.

How about George W. Bush? The man was widely regarded as personally honest but eight members of his administration got caught up in the Jack Abramoff lobbying scandal. In total, there were 21 criminal convictions and guilty pleas from 43's administration and 10 prison sentences -- including Vice President Dick Cheney's Chief of Staff Scooter Libby, who had his sentence commuted by President Bush and recently received a full pardon from President Trump.

Bill Clinton's administration was certainly beset by scandal -- but much of it was self-inflicted and sexual in nature, most notoriously the Monica Lewinsky affair that came to light thanks to special prosecutor Ken Starr's Whitewater Investigation. Shades of 1998 are back on the radar these days, as Supreme Court nominee Brett Kavanaugh and current Deputy Attorney General Rod Rosenstein both served on Starr's investigation.

But Clinton's executive branch had only two convictions and guilty pleas: former Housing and Urban Development Secretary Henry Cisneros, who pleaded guilty to lying about payments to a mistress dating back to his time as mayor of San Antonio, and Ronald Blackley , a chief of staff to Agriculture Secretary Mike Espy who lied to an independent counsel looking into his boss for accepting improper gifts. Espy was acquitted and is currently running for Senate in Mississippi.

President George H. W. Bush presided over a comparatively clean administration, with only one conviction and prison sentence doled out to a senior member of his administration. Catalina V. Villalpando, the US treasurer, whose name was printed on all dollars, pleaded guilty to three felony counts after leaving office, including tax evasion, obstruction of justice and making false statements.

Which brings us to Saint Ronald Reagan. He was an honest man, but it might surprise many of his conservative acolytes today that his administration saw a whopping 24 convictions and guilty pleas over eight years. They were largely related to the Iran-Contra scandal, whose most famous protagonist today is probably Oliver North, formerly of Fox News and now the NRA.

Those investigations ultimately ensnared his Secretary of Defense Caspar Weinberger and two national security advisers, John Poindexter and Robert McFarlane, among others. Many of the convictions were for withholding information or lying to Congress . Some of the convictions were overturned on appeal and ultimately no one from the Reagan administration served jail-time -- thanks in large part to a series of pardons issued by President George H. W. Bush, who maintained that the special counsel investigation was politically motivated.

The one-term administrations of Jimmy Carter and Gerald Ford may have been a time of economic malaise, but neither White House saw a single conviction or jail time while in office, though Ford's Agriculture Secretary Earl Butz was later convicted of tax evasion.

Then there was Richard Nixon, the only president to resign from office. After he won a 49-state landslide re-election in 1972, the Watergate scandal consumed his administration.

The dozens of Nixon administration and campaign aides convicted, at least 10 of whom were primary players who served jail time in connection with Watergate, were not small players. Even before Watergate broke wide open, Nixon's "law and order" Vice President Spiro Agnew resigned i n disgrace for accepting bribes when he was governor of Maryland.

But the Watergate break-in and subsequent cover-up claimed large portions of the powerful West Wing staff and Cabinet confidants -- including the attorney general and campaign chairman John Mitchell, the White House chief of staff H.R. Haldeman, senior domestic policy adviser John Ehrlichman and other White House and senior campaign staff. Nixon -- whose lawyer James St. Clair said had ordered him to make the case that "he is as powerful a monarch as Louis XIV, only four years at a time" -- was of course pardoned by his successor, Gerald Ford after his resignation.

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This is a sobering and sordid list -- and while the bulk of these convictions and pleas occurred under Republican presidents, they're all a reminder that every administration has its scandals and bad apples. But this reality check also reveals that not every administration is the same when it comes to creating a culture of corruption -- and less than two years into his administration, President Donald Trump may be on pace to equal or exceed the record set by his swampiest predecessor, Richard Nixon.