0 a person who is easy to persuade to do, say, or believe things that help a particular group or another person politically: --
All of these activists, claimed the authorities, were the useful idiots of a red plot.
While the former dictator may fool himself, and a few useful idiots on the right, he will not fool us.
He said he was sick of "the whining of Bush and Blair's useful idiots in the liberal media".
Communist insiders, following Lenin, described people who wanted to believe such fairy tales as "useful idiots".