He CHEATED to win the 2016 election. He lied about his opponents, in violation of the law, and he covered up his won scandals while falsely accusing Clinton of being a criminal. That's "fraud".
He accepted help from and coordinated the the Russians and with Julian Assange, for the hacking and release of the DNC emails, and then Roger Stone lied to the FBI about it.
He tried to overthrow the government, when the American people voted him out of office in 2020, after his failed covid response killed over a half a million Americans and left more than 10 million people sick with the disease.
Now he claims if he doesn't win re-election that it's "rigged" and has refused to accept the results of the election unless he wins. He is an "enemy of the Constitution, and deserves to be put down like the scurvy, rabid dog he is, before more people get killed.