Rubio still hopeful on Iowa campaign trail Marco Rubio campaigned in Iowa on Tuesday ahead of the state's presidential caucus on February 1st. The Senator is far behind Donald Trump and Ted Cruz in the polls, but may benefit from a strong third place as the top 'establishment' candidate. Rubio focused on his ability to bring the party together and on his strong religious faith at an event in Marshalltown. IMAGES AND SOUNDBITES