(Courtesy of Chris Coons' Facebook page)

Though O'Donnell has trailed Coons for months, she's remained a high-profile candidate because of a tendency to stick her foot in her mouth.

Some of O'Donnell's more notable quips include embracing witchcraft, denouncing masturbation and questioning the separation of church and state. 

O'Donnell's most recent foray with the public spotlight involves a story on Gawker in which a writer alleges having had a one-night stand with the candidate on Halloween three years ago. The story includes pictures of an allegedly intoxicated O'Donnell in a ladybug costume.

The race has also garnered national attention because both President Barack Obama and Vice President Joe Biden spent time in Delaware campaigning for Coons. Biden held the seat for more than three decades before becoming vice president.

Coons has long led O'Donnell by double digits in the polls.

Though the New York Times’ Five Thirty Eight blog run by well-known statistician Nate Silver showed Coons and O'Donnell in a tight race in July, the gap widened significantly since then.

Silver had Coons with a 100 percent chance of winning as early as Oct. 13.

On Nov. 1, Silver predicted the Democrat would win with 56.8 percent of the vote, while the Republican would trail with 40.5 percent.