Mark Sanford: Trump lashes out at latest Republican challenger

Donald Trump has lashed out at Mark Sanford, the latest Republican to challenge the US president in the party's primary contest.

Mr Trump described Mr Sanford, a former South Carolina governor, and two other hopefuls as "badly failed candidates".

The president also mentioned Ms Sanford's extramarital affair with an Argentine woman in 2009.

It is seen as near impossible that anyone will take the Republican mantle from the president.

No sitting president in the modern era has lost the race to be nominee for their own party, and Mr Trump...