(COMBO) This combination of pictures created on February 25, 2016 shows top US presidential candidates (L-R) Republican Marco Rubio on January 14, 2016; Republican Ted Cruz on February 23, 2016; Democrat Bernie Sanders on on February 04, 2016; Republican Donald Trump on February 23, 2016; and Democrat Hillary Clinton on February 04, 2016. The candidates head to the Super Tuesday" primaries on March 1, 2016. Twelve states and one territory will caucus or cast primary votes, with more delegates up for grabs than at any other time in the presidential election cycle. / AFP / dsk - LEHTIKUVA / AFP