Democrat Joe Biden currently leads Trump in the Badger State by 6.4 percentage points in the RealClearPolitics polling average. However, the average includes an ABC News/Washington Post survery that shows the incumbent trailing by a whopping 17 percentage points. No other poll in the average has Biden leading by more than nine percentage points.
"I think the most reliable public poll is [the] Marquette University Law School poll," Walker told host Neil Cavuto. "That poll had Hillary Clinton up, six days before the  election, by 6 points. That same poll came out this week, and it has Joe Biden up by five points.
"So if I'm the Trump campaign, I'm looking at those numbers, and I say, 'Four years ago, the Democrat was up by six. This time the Democrat is up by five. That means we've got a fighting chance,'" Walker added.
The former governor added that Trump is more competitive in many states than the polls indicate.
"I think four years later now, with the riots, with the chaos, with all of the pressure and all of the abuse that people get for supporting the president in some places, I think they are even more likely to be underground in terms of talking to pollsters, so I think it is much closer," he said.
Walker, a diehard Green Bay Packers fan, also touted an endorsement of Trump by retired quarterback Brett Favre ahead of the president's rally in Green Bay Friday afternoon.
"Even Brett Favre came out today [for Trump] -- that's a big deal," said Walker.
In a tweet, Favre said he is voting for "what makes this country great: freedom of speech & religion, 2nd Amendment, hard-working tax-paying citizens, police & military."
"For me & these principles, my vote is for Donald Trump," wrote the 51-year-old nicknamed "The Gunslinger"