Donald Trump says he will support the Republican nominee if he fails to win it and he promises not to run as a third-party candidate
Trump: Best way for Republicans to win is for me to be the nominee.
Donald J. Trump is at the top of the Republican polls and signes the RNC loyalty pledge.
Ben Carson is right behind Trump in a new Monmouth University poll with 18%. In that poll Trump hits 30%. The highest he's had in the last few weeks.
Trump says that RNC has been treating with great respect.
Doug Heye: RNC does not get involved in primaries. Trump can't answer basic or serious questions on policy.
Katrina Pierson: He can be considered a "real" Republican.
S.E. Cupp: Trump RNC pledge inadvertently gives Democrats a big advantage. Donald Trump is not "anti-establishment" he's just inexperienced.
What is behind Dr. Ben Carson's surge? Tom Foreman reports.
Carson says what is on his mind.
Carson: There i