For Donald J. Trump’s most ardent supporters, the assassination attempt on Saturday was the climax and confirmation of a story that Mr. Trump has been telling for years.

It is the story of a fearless leader surrounded by shadowy forces and intrigue, of grand conspiracies to thwart the will of the people who elected him. A narrative in which Mr. Trump, even before a gunman tried to take his life, was already a martyr.

“They’re not coming after me,” he declared at the first rally of his 2024 campaign, last year in Waco, Texas. “They’re coming after you — and I’m just standing in their way.”

In the hours after the shooting — before the gunman’s name, much less a motive, was known — many Republican politicians and Trump supporters blamed Democrats and the news media. They pointed to portrayals of Mr. Trump as an authoritarian and anti-democratic force in politics, which they argued created a climate that made an attempt on his life inevitable.

“Dems and their friends in the media knew exactly what they were doing” in comparing Mr. Trump to Hitler, Donald Trump Jr. wrote on Sunday in one of several accusatory posts on X about his father’s shooting.

Others pointed to President Biden’s remarks on a call with donors last week in which he said, “It’s time to put Trump in a bull’s-eye.” Citing the speech, Mike Collins, a Republican congressman from Georgia, wrote on X: “Joe Biden sent the orders.”