Franklin Delano Roosevelt
What a dark day for American democracy it was - February 5, 1937, the day they arrested President Roosevelt.
The pretext for this assault on democracy was President Roosevelt's proposal of the Judiciary Reorganization Bill of 1937, which would have allowed President Roosevelt to appoint more members to the Supreme Court, which had blocked New Deal measures President Roosevelt had introduced to try to bring America out of the Great Depression. Supporters of the New Deal were particularly galled by the Supreme Court's decision the previous year throwing out New York's minimum wage law.
But some of President Roosevelt's opponents in Congress (including many conservative Democrats), the Supreme Court, and the military claimed the proposed bill was an assault on the Constitution - even though the Constitution doesn't say how many Supreme Court justices there should be, and Congress had changed the number of Supreme Court Justices many times in the past - and that Roosevelt's move was a dangerous power grab. So dangerous, in fact, that Roosevelt's proposal could not even be considered in Congress. Roosevelt's opponents claimed that he had violated the Constitution by even suggesting the idea, and had to be removed from office immediately; that Roosevelt and his supporters were such a threat to the established order that due process had to be dispensed with - if Roosevelt were put in prison, maybe there would be riots.
Therefore, on the morning of February 5, soldiers under the command of General Smedley Butler arrested President Roosevelt and deported him to Canada, still in his pajamas.