ROME — The Italian language does not want for colorful insults. There are curses upon a person’s dead relatives, ample anatomical exclamations and countless ways to call someone a moron.

But these days, it seems, one of the biggest put-downs of all is to call someone a do-gooder.

And on the lips of Matteo Salvini, the leader of the anti-immigrant League Party and Italy’s most powerful politician, the word “buonista,” or do-gooder, is a dangerous weapon.

“The European dream is being buried by the bureaucrats, the do-gooders and the bankers who are governing Europe for too much time,” Mr. Salvini said this past week at the introduction of a new alliance of far-right and populist parties before European parliamentary elections in May.

Or early this year, when he spoke scornfully of “the hotshot do-gooders,” those he equates with hypocritical limousine liberals or Pollyannish bleeding hearts, who “condemned to death thousands” by urging migrants to “come, come, come.”