Donald Trump told CNBC on Thursday he will either win with his frank and uncensored style of campaigning or enjoy a "very, very nice long vacation."

Republicans have long hoped Trump will pivot on his behavior, but in the "Squawk Box" interview, he said:

"I'm a truth teller. All I do is tell the truth. And if at the end of 90 days, I've fallen short because I'm somewhat politically correct even though I'm supposed to be the smart one and even though I'm supposed to have a lot of good ideas, it's OK. I go back to a very good way of life."

A string of unfavorable poll numbers and growing opposition from within his own party's congressional membership have made Republicans increasingly nervous that they have toxic nominee on their hands that could endanger the party's future.

In the wide-ranging phone interview, Trump insisted that President Barack Obama "absolutely" founded ISIS. He also discussed economic issues including regulation and infrastructure spending.

Trump initially made the ISIS comments on Wednesday.

Asked about them, he doubled down and said "[Obama] was the founder of ISIS absolutely, the way he removed our troops. ... I call them co-founders," he added, referring to his Democratic presidential opponent, Hillary Clinton.

Trump also stood by his remarks about the Second Amendment that Democrats interpreted as calling for violence against Clinton.



"On the Second Amendment everybody came to my defense because there was nothing said wrong. I'm talking about the power of the voter," Trump told CNBC. "Only the haters tried to grab onto that one."

However, Trump allowed for the possibility that his uncensored views may not result in a win.

"I think we're going to have victory, but we'll see," Trump said. "At the end it's either going to work or I'm going to, you know, I'm going to have a very, very nice long vacation."

The GOP presidential nominee also addressed criticism that he had made a mistake when it came to comments about the Muslim parents of a fallen American soldier, saying "it's been put to bed for a long time." The controversy erupted after Khizr and Ghazala Khan appeared at the Democratic Convention on July 28.

Trump also said Obamacare, high taxes and regulation are stifling business in the United States.



He said regulations are "making it virtually impossible to start new businesses, and a lot of old businesses are being hurt very badly."

"Obamacare is devastating businesses, I get it all the time," he said.

Trump's comments came during a stretch in which he has sought to focus on his campaign's economic message amid a series of controversies.

He laid out his economic plans in a speech in Detroit on Monday, but he has spent much of the week fighting off criticism for his subsequent comments about the Second Amendment.

Clinton called him out on the remarks on Wednesday, saying Trump's "casual inciting of violence" shows he does not have the temperament to be president.