Trump calls Bloomberg a debate 'lightweight'

Media mogul and former New York City mayor Bloomberg, 77, surprisingly announced his candidacy in November.

In an unusual move, Bloomberg is skipping early voting states, focusing instead on the larger states such as California, Florida and Texas that vote on March 3 - Super Tuesday - and beyond.

Ranked by Forbes as the eighth-richest American with an estimated worth of $53.4 billion, Bloomberg has previously been praised within the party for his advocacy and philanthropy on climate change and in fighting gun violence. He served as mayor of New York from 2002 to 2013.