Remember Carly Fiorina? It now seems forever ago, but in late September she was being heralded as the next big thing in the Republican primary field—the outsider candidate who could marshall establishment support, and finally slay the Trump dragon.

Now look at the polls. An NBC/Wall Street Journal poll Monday has her at 7 percent, running behind the much-maligned Jeb Bush. That’s down from 11 in late September. A CNN poll released Tuesday is even bleaker. She comes in fourth—tied with also-ran Chris Christie and behind Rand Paul, who’s on campaign deathwatch. That’s even worse than it seems, because in mid-September she was at 15 percent in the same poll, good for second place.

So what happened to Fiorina? There’s no single obvious explanation, but here are a few ideas.

Fiorina’s polling has correlated strongly with her debate performance. She surged after dominating the undercard at the first Republican debate in August, and after winning a promotion to the main stage for the second debate, she was the consensus winner there, too. After each debate, her numbers surged. But there hasn’t been a GOP debate for more than a month, since September 16.

In that time, her stock has plummeted. Fiorina has practically disappeared from the headlines in the last few weeks. She doesn’t seem to be as good at collecting “earned media”—attention in the press, more or less. Donald Trump and Ben Carson, in contrast, are great at creating controversies that get them on TV. John Sides at The Monkey Cage has been on a crusade to convince readers that Trump’s high polling, and any dips, are caused almost entirely by the level of media attention he receives. Carson’s statements about the Holocaust and gun control, or about the Umpqua massacre, may be derided by some, but they keep his name in the news—and they rile up supporters who see criticism of his remarks as persecution. (Fiorina pulled something similar off when she insisted she’d seen a video taken at a Planned Parenthood that did not exist, but that moment passed, and she hasn’t created another.)

People have been predicting the demise of Trump’s campaign since, well, before it existed, but the drumbeat actually grew after the second debate, in which he was generally said to have put in a subpar performance. But as Molly Ball points out today, that hasn’t happened—he’s really running.