Donald Trump, the presumptive Republican nominee for president, argued on Wednesday that elected officials who ran against him for president and now have declined to back him "should never be allowed to run for public office again."

During a speech in Bangor, Maine, Trump accused those who have declined to back him of violating a Republican National Committee pledge to support the eventual nominee. Trump, who waffled on the pledge before signing it, said he would have honored it, according to NBC News.

Those who haven't issued endorsements from the 2016 field include Sen. Ted Cruz (Texas), Ohio Gov. John Kasich, Sen. Lindsey Graham (S.C.), Wisconsin Gov. Scott Walker and former Florida Gov. Jeb Bush.

Earlier this week, The New York Times reported the RNC and Trump campaign were working to quash last-minute efforts to deny Trump the nomination. Trump has also said he would deny speaking slots at the convention to those who had not thrown their support behind him.

Editor’s note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims — 1.6 billion members of an entire religion — from entering the U.S.