There are more and more signs that Vice President Joe Biden is taking a very close look at running for president in 2016.

Recent conversations between Biden's associates and Democratic donors and operatives have led to speculation that Biden will challenge front-runner Hillary Clinton for the party's nomination.

"I think this is the Democrats having GOP envy," Charles Krauthammer said on "Special Report."

Krauthammer explained that the Republicans are having so much "fun" and getting so much media attention with their crowded, ever-growing field of contenders.

The Democrats don't want to stand on the sidelines for the next 18 months and simply coronate Clinton, Krauthammer said, adding that he believes Biden will indeed enter the 2016 race.

Watch the "Special Report" panel weigh in above.

Don't miss the Fox News-Facebook Republican presidential debate, Thursday August 6, live from Cleveland, Ohio at 9p ET, moderated by Megyn Kelly, Bret Baier and Chris Wallace.

Biden Celebrates 'Equal Pay Day' With ... Photo From Women's Locker Room?!

WATCH: Joe Biden Does Arm Curls While Chatting on the Phone

Watch: Best of Joe Biden at Today's Senate Swearing-In Ceremony