Social concerns
When the debate turned to social issues, traditionally a key concern of Republican voters, five out of seven of the candidates said they would support an amendment to the US constitution banning same-sex marriage.
Mitt Romney is the current front-runner in the Republican field
Ron Paul said he opposed one, but added that governments should not be involved in marriage policy at all.
Mr Cain said individual states should be allowed to decide same-sex marriage policy on their own.
Mr Romney and Mr Santorum said they opposed a law passed in December 2010 to allow gays and lesbians to serve openly in the military.
Mr Gingrich said that the US Army and Marine Corps overwhelmingly opposed ending the ban on gays in the military, so he too opposed doing so.
However, a 2010 Pentagon survey of 115,000 service members found that 70% believed the impact on their units would be positive, mixed or of no consequence at all.
Other issues discussed included abortion, immigration and the place of church and faith both in the state and in the life of a president.
http://www.bbc.co.uk/news/world-us-canada-13751433