The list of Republican presidential candidates seems to be getting longer by the day. On Wednesday, Rick Santorum entered the race, and on Thursday, former New York Governor George Pataki is expected to do the same. Larry J. Sabato, director of the University of Virginia Center for Politics, now counts 18 likely contenders. And yet, only a few have much of a real chance of winning: Jeb Bush, Scott Walker, and Marco Rubio lead the pack, followed by Rand Paul and Ted Cruz.

So why, if you're Pataki, run at all?

“Pataki—I’m puzzled about this,” Sabato told the New Yorker last month. “I don’t even know what he’s been doing. Has he been on corporate boards?”

Indeed, Pataki hasn't held office since 2006, and he declined to run for president in the past two cycles. But a number of other 2016 entrants are equally puzzling: Carly Fiorina, a former Hewlett-Packard CEO, who has never held public office; Ben Carson, a neurosurgeon and Tea Party favorite; Mike Huckabee, the ex-Arkansas governor. Even Donald Trump is threatening to run.

Why run as a dead-in-the-water candidate? Maybe God tapped them to run (“I feel fingers,” said Carson). Maybe they want to influence the public policy debate. Maybe they want to return to the spotlight. Or maybe they genuinely believe they can win. After all, in 2012, five different candidates held the lead at some point, including pizza mogul Herman Cain and former House Speaker Newt Gingrich. Mitt Romney won, as expected, but for a while there—especially after Santorum’s early wins in Iowa, Minnesota, Colorado, and Missouri—2012 looked like it could be anyone’s election.