Jeff Weaver said Sanders has the best chance of beating Trump.
Trump said that the 2012 convention was "the lowest rated in the history of the convention."
"But I think you have to pay attention if a potential president of the United States talks to you."
"I am who I am," the presumptive nominee said.
"It's like the football team that can't get it over the goal line," he said.
Clinton continued her series of video attacks against Trump.
"He's certainly a capable guy," Trump said of Cruz.
The committee thanked the entire GOP field for their efforts.
Priebus said the focus will now be on the Democratic opponent.
Trump said he would create a "world-class finance organization."