Real estate mogul Donald Trump has increased support among republicans since last June, his numbers increasing by 6 percentage points despite the way he criticized John McCain's war record. Now at the top of the 2016 presidential field based on the CNN poll

Released last Sunday, Trump edged out his main rival, Jeb Bush.

Now backed by 18% of the republicans, the numbers, however are not quite firm as his lead over the former Florida governor (who is second with 15% support) is within the poll's margin of error.

Trump and Bush were joined at the top by Wisconsin Governor Scott Walker, who is the third and last to gain double digit support at 10%.

According to CNN, 51% of the registered republican voters said that they "see the field as wide open" which means that it's too soon to put their confidence into one candidate with whom they will ultimately support in next year's elections.

On CNN's "State of the Union," Trump said that the poll results did not surprise him.

He shared, ""There is a movement going on. This is more than me. "People are tired of these incompetent politicians in Washington that can't get anything done."

Despite Trumps confidence, CNN also said that his popularity does not translate so much to the broader pool of voters: overall, 59% of all registered voters have an unfavorable opinion of the billionaire, although the number dips nearer to 42% among GOP voters.

South Carolina senator Lindsey Graham thinks that Trumps campaign is a danger to his supporters.

Speaking with ABC's George Stephanopoulos, he said, "I would ask the Republican Party why most major companies are firing Mr Trump, and I don't think we should hire him."

"I'm not taking on voters, I am taking on an idea that I think he's appealing to the dark side of American politics. He is not offering solutions to hard, complicated problems. He is basically selling fear and prejudice."

If he gets to earn a spot on the debate stage during the first televised Republican Debate on August 6, Graham said, "I'm going to talk to people in Iowa and New Hampshire and South Carolina about the threats we face, why I'm the best qualified to be commander-in-chief, and why Mr. Trump, while he says a lot of controversial and loud things, is not qualified to be commander-in-chief."

For emphasis, Graham said, "he cannot win an election that we cannot afford to lose."