Trump Pledges Loyalty to GOP An eventual third-party run just became a lot less likely By Michael Harthorne, Newser Staff Posted Sep 3, 2015 1:42 PM CDT 115 comments Comments Donald Trump signed a Republican loyalty pledge today promising not to run as a third-party candidate should he not secure the GOP nomination. (AP Photo/Richard Shiro) (Newser) – Donald Trump has come to heel, agreeing to support the eventual Republican presidential nominee and not run as a third-party candidate, the AP reports. Despite being the only candidate to publicly mull a third-party run during the August GOP primary debate, Trump signed a party loyalty pledge today. The pledge was circulated by the Republican National Committee to all candidates. Prior to Trump agreeing to the loyalty pledge, sources tell CNN, most supporters calling into his campaign about the pledge wanted Trump not to sign. While the pledge is not a legally binding document, Trump says he sees "no circumstance under which I would tear up that pledge," FOX News and NBC report. According to the AP, a third-party run would have made the path to the presidency much easier for the eventual Democratic candidate.