When Cantor was asked to weigh in on a new poll from the network showing Trump making headway in picking up Republican support for a potential campaign, the Virginia Republican signaled he would not support the billionaire if he ran for president.
"No, I don't think he is really serious when we see a campaign launch on the birther issue," he said.
In recent weeks, Trump has made headlines and sparked controversy by repeatedly raising skepticism over whether the president was born in the United States. Senior White House adviser David Plouffe took aim at Trump last weekend in the wake of his persistence in pushing the conspiracy theory issue. He called the antics "sideshow behavior" and said there's "zero chance" voters would elect the potential candidate to the White House.
"I know for a fact that I am the only candidate they are concerned with," said Trump to the New York Daily News in responding to the criticism earlier this week. "They are very concerned because I am challenging him as to whether or not he was born in this country where there is a real doubt."