Rick Santorum is expected to announce the end of his presidential bid later tonight on Fox News.

Another announcement is to be made, with Santorum informing which of his fellow Republican candidates he will be endorsing.

Reports from the Republican side have told CNN that Santorum will be the third Republican candidate to drop out since the caucuses on Monday, following Mike Huckabee who ended his campaign that night, and Rand Paul suspended his campaign earlier today.

Back in the 2002 Presidential race, Santorum came second only to Mitt Romney, despite his controversial comments about homosexuality, which he compared to bestiality.

This time around, with 17 potential Republican candidates, and the likes of Donald Trump and Ted Cruz to compete with, Santorum could not garner a repeat of the support he received last time around.