On Thursday morning President Donald Trump took to Twitter to attack special prosecutor Robert Mueller's investigation into the president's campaign, calling it a "WITCH HUNT."
The attack came the day after reports suggested the investigation expanding and looking at whether Trump attempted to obstruct justice.
This isn't the first time the president has attacked the special prosecutor's investigation into ties between the Trump campaign and Russia. Given the average length of such investigations and Trump's impulsiveness, it likely won't be the last.
A chart from Compass Point's Issac Boltansky and Lukas Davaz shows that the average length of special counsel investigations, dating back to Watergate, last on average 904 days.
The longest such investigation was the investigation into President Bill Clinton's Whitewater real-estate deals. That investigation eventually morphed with the Monica Lewinsky scandal. It went on for 2,978 days.
The investigation into the arms deals around the Iran-Contra affair under President Ronald Reagan lasted 2,420 days.
It has been 29 days since Mueller was appointed.
Based on history, Boltansky and Davaz wrote, this isn't going away anytime soon.
"We remain skeptical regarding the potential for congressional action against President Trump as the obstruction claims will ultimately be assessed through a political lens, but the overhang will persist," the analysts wrote in a note to clients. "The congressional investigations appear to be moving at a measured pace and the average length of special prosecutor's investigation is three years."
Here's the chart:
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