In the battle for 1600 Pennsylvania Ave., some candidates get put in the "it's probably not happening for you, buddy" category.

"As much as I like Carly Fiorina, she's got a real uphill battle in the presidential campaign," Mary Kissel from The Wall Street Journal said on "Varney & Co."

"A lot of people say well, Bernie Sanders, good ideas, nice guy, but he can't defeat Republicans," Sen. Bernie Sanders said in a recent interview.

But history shows us no candidate can be counted out of the running, and you don't have to look very far to find examples.

Just take these two guys right here — John Edwards in 2004 and Rick Santorum in 2012.

Santorum was definitely a long-shot candidate, but right when people started to push him aside, he saw a huge late surge. It started when he won the very important Iowa caucuses. (Video via Rick Santorum)

"Game on," were Santorum's first words in his victory speech after the surprising win.

He went on to win caucuses in Colorado, Missouri and Minnesota and more even into late March, all while pulling the eventual nominee, Mitt Romney, further to the right, which hurt him in the general election against President Obama. (Video via Rick SantorumCNN)

In '04, Edwards surprised many when he pulled ahead of front-runner Howard Dean with a second-place finish in Iowa. (Video via John Edwards)

"The people of Iowa tonight confirm they believe in a positive, uplifting vision to change America," Edwards said after placing behind John Kerry in 2004.

Edwards went on to win the South Carolina primary but could never edge out eventual nominee John Kerry. He was able to turn that momentum into a VP slot in the general election though. (Video via John Edwards)

So to you front-runners, always remember...

"Objects in your mirror, may be closer than they appear," Edwards said after the Wisconsin primary in 2004.

This video includes images from Getty Images and music from Lee Rosevere / CC BY NC 4.0.