Who said a democracy if you can keep it?US is a Republic which elects its representatives by democracy.
It is clear that Trump didn't accept that election results... He fought them in court and lost 60+ times mainly due to lack of any credible evidence...
Trump was clearly told and accepted that he lost the election but kept telling his supporters he won.
He then arranged for an armed crowd to come to the capitol and told them they had to fight to over turn the election and tried to lead them.
So that is bad enough, there is more
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He also had arranged for fraudulent electoral representatives to come the capitol (from Arizona) to vote for him.. As stupid as this sounds it was attempted... The guys on World's dumbest criminals still goto jail..
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He also pressured an election representative in Georgia to 'find' the exact number votes he would need to win the state. That is highly illegal..