Transcript for Ben Carson the Likely Target at GOP Debate Amid Latest Headlines
The race for president now and the candidates facing off in tonight's big debate. Donald Trump and Ben Carson will be center stage again. A new poll shows they are neck and neck. Last night trump giving a preview of the attacks Carson may face and trump will join us live in a moment but first ABC's Tom llamas is there in Milwaukee for tonight's showdown. Good morning, Tom. Reporter: Robin, good morning to you. The debate takes place here at the Milwaukee theater and you're right, trump spoke in front of a huge crowd last night putting the pressure on Dr. Ben Carson but this morning we've looked into the stories that he's been questioned about and some are checking out. Overnight, Donald Trump unleashing on Dr. Ben Carson and the new scrutiny over Carson's life story. This is the only election in history where you are better off if you stab somebody. Reporter: Trump and Carson now neck and neck in the polls, the retired neurosurgeon forced to answer questions about his violent youth. If you try and hit your mother over the head with a hammer, your poll Numbers go up. A lot of weird things are happening. This is a strange election, isn't it? Reporter: Carson standing by the stories he wrote about in his autobiography and talks about on the campaign trail like turning his life around as a young man after trying to stab a fellow teen. Carson's campaign pointing to an article in "Parade" magazine in 1997 where his mother corroborates the storytelling the reporter, oh, that really happened and after "The wall Street journal" reported discrepancies in Carson's account of an incident at Yale where he said he was honored as the most honest student after a class hoax involving a bogus test a fellow student who staged the hoax telling ABC news, Carson was not lying saying, quote, I think he got it close to right. I do not remember this level of scrutiny for one president Barack Obama when he was ruvening, in fact, I remember just the opposite. Reporter: But as other candidates say, this is all fair game, Carson finding some support from senator Marco Rubio. I know everything I need to know about Ben Carson. He came from a poor family with no advantages in life and worked hard and became one of the world's most renowned neurosurgeons. That's all I need to know. Reporter: The debate is tonight. It'll be two hours and starts at 9:00 eastern. There will be eight gop candidates on the main stage. Governors Christine and Huckabee did not make it. So much focus going on with Carson, unclear how much policy they'll be able to squeeze in.
This transcript has been automatically generated and may not be 100% accurate.