Since Donald Trump's entry into the GOP presidential race, Wisconsin Gov. Scott Walker has seen his poll numbers sinking steadily in the all-important state of Iowa.

Walker had been leading for months in Iowa, with political analysts believing his support in the neighboring state would lead to a crucial victory in January's caucuses. 

But now, a Monmouth University poll shows Trump and Ben Carson tied for the lead at 23 percent, in front of fifth-place Walker by 16 points.

On "America's Newsroom" today, Bill Hemmer asked Walker about his sinking poll numbers.

Walker dismissed the polls, saying the only one that matters is the "one on Election Day," and that he was saying that even when he was leading. 

Walker said he's confident in his message and believes voters will eventually turn to someone who has been "tested."

"I've been tested like none other in this campaign and I've got a plan to make this country great again," said Walker.

He pointed out that at this time in 2008, the leaders on the GOP side were Rudy Giuliani and Fred Thompson, while Hillary Clinton was the frontrunner for Democrats.

Walker acknowledged that voters seem to want a candidate from outside of Washington. He said he considers himself an "outsider," who has taken on the "Washington-based power structure" in his own state.

Watch the interview above, as Walker also discusses his criticism of Jeb Bush on the Iran deal.