Mindset of a presidential candidate

NEW YORK (FOX 5 NEWS) - President of the United States is a job only 43 men in the history have held.

This year, 23 people ran for president. Now only five are left. And as we've seen so far, it's been a bruising campaign.

So we set out to look at the mindset of what makes someone want to run for president. It's not the friendliest process in the world. Running for president means your life becomes an open book. And as we've seen with this campaign cycle, it can get alarmingly personal.

So what does it take for someone to want to run for president, to look at the current state of affairs and decide 'I'm the right man or woman for the job'?

Stanley Renshon is a professor at CUNY and specializes in political psychology.

"I think presidential candidates are distinguished by the level of their ambition -- number 1," he said. "I think if you have a scale of 100, most ordinary people are the 25 to 45 percent range. The heads of companies are probably in the 60 to 65 percent range. And most presidential candidates who stick with it and aren't just doing it on the fly are really in the 90 to 95 percent range."

In addition to ambition, Renshon says resilience is a key part of what makes a successful candidate tick.

"It takes a lot -- it takes a couple of years to plan a presidential run and do it," he said. "And not everybody is willing to do that even though they might think of themselves in their wildest dreams as being president."

And as these candidates vie for the hearts and minds of Americans, what is in their own minds can make your head spin.