From Mike Allen writing at Politico:
A close associate tells POLITICO that Donald Trump plans to sign a loyalty pledge Thursday that would bind him to endorse the Republican nominee, and would preclude a third-party run. Trump made the stunning decision, which he has long resisted, to avoid complications in getting listed on primary ballots, and to take away an attack line in the next debate, the associate said.
Trump, who has led the GOP field in poll after poll, has long viewed the threat of a third-party candidacy as priceless leverage – and even used that word when he refused to take such a pledge in the first debate, on Aug. 6.
So his decision to give it up is a sign that he increasingly wants to show his campaign is real and not a stunt. The colorful magnate is also trying to make that point by adding staff in key states, issuing position papers, and pursuing access to primary ballots throughout the country.
Read the rest of the story at Politico.