Marco Rubio (43): The junior US senator from Florida launched his campaign on April 13 with a conference call to his biggest backers. The son of Cuban immigrants, his campaign is all about rescuing the American Dream – with a strong focus on the economy. At the 2013 Values Voter Summit he said: "If we're serious about saving the American Dream, we can't stop talking about [social issues]... We can't stop talking about them because the moral wellbeing of our people is directly linked to their economic wellbeing."

Rubio was born into a Catholic family and baptised into the church, attended a Mormon church for few years as a child (and was baptised again into the Mormon faith), but returned to the Catholic Church and took First Communion in 1984, according to a 2012 interview with Christianity Today.

He says in his 2013 memoir 'An American Son' that in the early 2000s his wife, Jeanette, started attending a Southern Baptist church with their children – Christ Fellowship in Miami. Rubio says the church "sparked a spiritual awakening in Jeanette's life, and eventually in mine, too".

But theologically he hadn't left the Catholic Church, he says, and in 2004 he felt called back. His four children have now also taken First Communion and they all attend Mass regularly, but the family still frequents Christ Fellowship and he gives generously to the church's ministry. He says the teaching at the evangelical church gave him a fresh appreciation for the meaning behind the tradition and liturgy in Catholicism.

Rubio also writes in his memoir of the importance of keeping faith in keeping personal ambition in check: "Our temporal ambitions are infinitely less important than our spiritual progress, but they are the stuff of life, too, and often beguiling, and they tempt us constantly to misplace our priorities... We all crave to make our mark in this life, and sometimes forget that our place in the next one matters more. I have been ambitious for worldly success. I hope I have been for the right reasons."

He upholds the teaching of the Catholic Church on gay marriage and abortion. In 2013 he co-sponsored a bill to ban abortions after 20 weeks, but allowed some exceptions, including in cases of rape and to protect the life of the mother. He thinks gay marriage legislation should be decided at a state-level, and was disappointed that the law on same-sex marriage in Florida was changed through the courts.