Trump tries to assert his dominance

Donald Trump’s private meeting Thursday with Senate Republicans – designed to foster greater party unity ahead of the national convention in Cleveland — grew combative as the presumptive presidential nominee admonished three senators who have been critical of his candidacy and predicted they would lose their reelection bids, according to two Republican officials with direct knowledge of the exchanges.

Trump’s most tense exchange was with Sen. Jeff Flake (R-Ariz.), who has been vocal in his concerns about the business mogul’s candidacy, especially his rhetoric and policies on immigration that the senator argues alienate many Latino and other voters in Arizona.

When Flake stood up and introduced himself, Trump told him: “You’ve been very critical of me.”

“Yes, I’m the other senator from Arizona – the one who didn’t get captured – and I want to talk to you about statements like that,” Flake responded, according to two Republican officials.

Flake was referencing Trump’s comments last summer about the military service of Sen. John McCain (R-Ariz.), who was a prisoner of war during the Vietnam conflict. Trump questioned whether McCain was a war hero because he was captured.

Flake told Trump that he wants to be able to support him – “I’m not part of the Never Trump movement,” the senator said – but that he remains uncomfortable backing him, the officials said.

Trump said at the meeting that he has yet to attack Flake hard, but threatened to begin doing so.

Flake’s spokesman did not immediately reply to a request for comment.

Trump also called out Sen. Mark Kirk (R-Ill.), who withdrew his endorsement of Trump last month citing the business mogul’s racially-based attacks on a federal judge, and said he did not approve of the senator’s action, said the officials.

Characterizing Kirk as a loser, Trump vowed that he would carry Illinois in the general election even though the state traditionally has been solidly Democratic in presidential contests. Kirk did not attend the meeting with Trump.

Trump also singled out Sen. Ben Sasse (R-Neb.), who has refused to support Trump and has emerged as perhaps the most vocal advocate for a third-party candidate. Sasse declined to speak with reporters as he left the meeting.

At one point during the gathering, Trump turned to the Nebraska senator and said, "You must want Hillary," according to a source in the room. Sasse, who has vowed not to vote for Trump or Hillary Clinton, did not respond, the source said.