President Donald Trump has tweeted that the investigation of collusion between Russia and Trump’s presidential campaign is “ … the single greatest witch-hunt in American political history.” If so, then the investigation is also the most successful witch hunt in history, accounting for the conviction of four campaign insiders including Paul Manafort, a Trump campaign manager. A recent episode of the TV show "Frontline" compiled reports from major newspapers and television news networks, including FOX News, to give an overview of the on-going investigation.

The investigation stems from attempts by Russian agents to supply the President’s election campaign with information that would prove damaging to the campaign of Trump’s opponent, Hillary Clinton. Much of the information was in the form of emails that had been stolen from members of the Clinton campaign.

Witch hunt: the hunters

James Comey (FBI Director 2013-2017), launched the investigation into connections between the Trump presidential campaign and the Russian government. The FBI director was later fired by the President. In an interview with NBC’s Lester Holt, President Trump admitted the firing was in response to Comey’s decision to continue the on-going investigation of collusion between the Russians and the Trump Campaign.

After the firing of Comey, the investigation continued under the Justice Department’s newly named Special Counsel Robert Mueller.

Witch hunt: the witches

The initial go-between for Russian agents and the Trump campaign was George Papadopoulos. While working as a foreign policy advisor to the Trump Campaign, Papadopoulos was approached by a Russian agent offering Trump’s campaign access to the Clinton campaign’s stolen emails.

When questioned by investigators, Papadopoulos denied his role in the espionage. Papadopoulos has since pleaded guilty of lying to a federal investigator about his contacts with the Russians.

On behalf of the Russian government, Natalia Veselnitskaya met with members of the Trump campaign, including Donald Trump Jr, Jared Kushner, and Paul Manafort.

According to the New York Times, in the meeting, Veselnitskaya offered the Trump campaign access to what has been called “incriminating” information against Hillary Clinton. Records of this meeting seem to be the most direct evidence of collusion between high ranking members of the Trump campaign and the Russians.

According to the Justice Department, as a result of the on-going investigation, Paul Manafort, the former Trump Campaign Manager and his deputy, Rick Gates have since been convicted of multiple felonies including failure to register as foreign agents.

While working for Trump’s transition team, Retired Army General Michael Flynn had been in contact with Russian Ambassador Sergey Kislyak.

When questioned by the FBI, Flynn denied any conversations. PBS Frontline reports, Flynn later pleaded guilty about lying to the FBI about his contact with the Russian Ambassador.

The actions of Attorney General Jeff Session have also come under scrutiny. CSPAN coverage shows, that during his confirmation hearings Sessions was asked about contact between Russians and the Trump campaign. Sessions testified that he was “…not aware of any of those activities” and that he “… did not have any communications with the Russians.” It was later revealed by the Washington Post, that Session himself had indeed met with a Russian ambassador at least twice during the campaign.

Witch hunt: the cover-up

According to Robert Bennett, President Clinton's attorney during the Lewinski investigation, “Improper acts, even if they are in and of themselves not criminal, amount to an intent to obstruct justice.” By that standard President Trump may well be guilty of obstructing justice.

According to notes of then FBI Director Comey, in a one-on-one meeting with the President, Trump requested Comey’s “personal loyalty.” Comey viewed the request as an attempt to intimidate the FBI Director and possibly obstruction justice. In a later one-on-one meeting between the President and the then FBI Director, the President asked that Comey “let it go” when referring to the FBI’s criminal case against General Flynn. In an interview with NBC’s Lester Holt, the President admitted the firing of James Comey was in response to Comey’s decision to investigate collusion between the Russian and the Trump Campaign. In the NBC interview, the President seems to clearly admit his motive was to obstruct a criminal investigation.

It is said, in politics the cover-up is often worse than the crime. In what may be the President’s most direct involvement in the Russian scandal, evidence suggests that Trump personally drafted a memo designed to create a false cover story about his campaign’s meeting with a representative of the Russian government. According to Robert Bennett, President Clinton’s attorney during the Lewinski investigation, “Improper acts, even if they are in and of themselves not criminal, amount to an intent to obstruct justice.” By that standard President Trump may well be guilty of obstruction of justice.