In a combative speech filled with insults, Trump mocks Biden’s Stutter and vilifies migrants and others.

Early in his remarks at what was effectively his first campaign rally of the general election, former President Donald J. Trump on Saturday blasted President Biden’s State of the Union address as an “angry, dark, hate-filled rant” that was more divisive than unifying.

Then, in the nearly two hours that followed, Mr. Trump, speaking in Rome, Ga., used inflammatory language to stoke fears on immigration, and repeated his false claim that the 2020 election was stolen from him.

The former president, who faces four criminal cases, called the press “criminals.” And he mocked President Biden’s stutter and revived a litany of grievances against political opponents, prosecutors and television executives.

Mr. Trump told thousands of his supporters gathered at the rally that “everything Joe Biden touches” turns to filth, though he used an expletive to describe the result. “Everything. I tried finding a different word, but there are some words that cannot be duplicated.” (He used the word, or a variant, at least four times in his speech.)

The former president’s speech in Georgia, a key battleground state that he narrowly lost in 2020, underscored that Mr. Trump is not likely to temper the ominous and at times apocalyptic vision that has animated his campaign, even as his last remaining Republican rival has dropped out and the general election has come into focus.

As he has in the past, Mr. Trump insisted that the biggest danger facing the United States was his political opponents, whom he labeled “the threat from within,” a turn inward that has alarmed experts for its similarity to language used by totalitarian leaders.