Former Republican National Committee chairman Michael Steele says he believes Donald Trump will be the Republican Party's nominee in the general election.

"I'm gonna say, and I know people are gonna scratch their heads and go, 'what?' but I don't you can," Steele said to radio host Rich Zeoli on 1210 WPHT when asked if someone could stop Donald Trump. "That window has closed and I think Donald Trump effectively closed it over the last couple of months."

Asked if he thought Trump would be the nominee, "you tell me who stops him and when do they do it," said Steele. "He's polling anywhere from 33 to 35, 36% in every poll in the country. He's now tightened the space between him and Cruz in Iowa. Cruz is still in the lead, but Cruz is slipping. He's down two points and Trump is up a couple points."

"So, you tell me who does it and you tell me when they do it. Folks start voting in two and a half weeks. You tell me that 33%, that 40% nationally, he didn't just drill it down to a New Hampshire or an Iowa, where he's leading by double digits, except against Cruz in Iowa where he's much closer, but he's at 27, 25. Cruz is at 24, 23, and he's at 22, 21. You think those percentages are just going to dissipate."

Steele said he talked to people in Iowa and many first time voters were going to go out and support Trump.

"So, I don't see how that momentum gets stopped right now, I don't know who breaks it. Come on, you had eight months. You had eight months to take him down."