Republican US presidential candidate and former Governor Jeb Bush waves to the audience at the Fox Business Network Republican presidential candidates debate in North Charleston, South Carolina, January 14, 2016. [Photo/Agencies]

Once regarded the front-runner of the Republican field, former Florida Governor Jeb Bush's favorability numbers with Republican primary voters has tanked since last July despite his formidable campaign war chest and solid support within the party establishment.

The son of former President George H.W. Bush and the brother of former President George W. Bush, Jeb Bush also becomes a target of anti-politician sentiment of this election cycle.