I think she's possibly the _clearest_ example of this in recent years; there've been others (realistically, "screwed up, or is perceived to have screwed up, the economy" is one of the more common reasons for national leaders to get their marching orders), but the sequence of "deranged budget proposal, catastrophic market crash, no more Liz" was just perfect. She didn't even, in the end, really _do_ anything; even the suggestion that she might do the things that she wanted to do was enough to cause a crisis.
(With Trump, the dynamic is a bit different, at least for now; he claims to want to do all sorts of absolutely bonkers things, and the markets are generally going "well, yeah, but you're not really going to, are you?")