Donald J. Trump’s closing rally at Madison Square Garden on the second to last Sunday before the election was a release of rage at a political and legal system that impeached, indicted and convicted him, a vivid and at times racist display of the dark energy animating the MAGA movement.

A comic kicked off the rally by dismissing Puerto Rico as a “floating island of garbage,” then mocked Hispanics as failing to use birth control, Jews as cheap and Palestinians as rock-throwers, and called out a Black man in the audience with a reference to watermelon.

Another speaker likened Vice President Kamala Harris to a prostitute with “pimp handlers.” A third called her “the Antichrist.” And the former Fox News host Tucker Carlson mocked Ms. Harris — the daughter of an Indian mother and a Jamaican father — with a made-up ethnicity, saying she was vying to become “the first Samoan-Malaysian, low IQ former California prosecutor ever to be elected president.”

By the time the former president himself took the stage, an event billed as delivering the closing message of his campaign, with nine days left in a tossup race, had instead become a carnival of grievances, misogyny and racism.

If the parade of speakers felt at times like a Republican National Convention reunion — Senator JD Vance of Ohio, Mr. Carlson, Vivek Ramaswamy, Alina Habba, Lee Greenwood, the Trump family all appeared — they seemed to have returned for a bonus fifth night that was more inflammatory than the original in July.

The rally served as a capstone to an escalating series of remarks from Mr. Trump, who has repeatedly said in recent days that one of the gravest threats that America faces is “the enemy within.” Democrats have cranked up warnings of Mr. Trump’s descent into authoritarianism as John F. Kelly, the former Marine general who was his longest-serving chief of staff, warned that Mr. Trump met the definition of a fascist.